Remove input/output typealiases for RPC methods (#1937)

Motivation:

The generated code for v2 includes typealiases for the input/output types for each RPC method. These typealiases end up making things less clear to the end user as they must follow the typealias to know what type is being used.

Modifications:

- Adjust `GRPCCodeGen` (both for the client and server) to not generate typealiases for the input/output types.
- Adjust `TestService` to use the actual message types.

Result:

The generated code will use the actual message types for the input/output types.

Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift

@@ -84,25 +84,25 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         internal protocol Hello_World_GreeterClientProtocol: Sendable {
             /// Sends a greeting.
             func sayHello<R>(
-                request: ClientRequest.Single<Hello_World_Greeter.Method.SayHello.Input>,
-                serializer: some MessageSerializer<Hello_World_Greeter.Method.SayHello.Input>,
-                deserializer: some MessageDeserializer<Hello_World_Greeter.Method.SayHello.Output>,
+                request: ClientRequest.Single<Hello_World_HelloRequest>,
+                serializer: some MessageSerializer<Hello_World_HelloRequest>,
+                deserializer: some MessageDeserializer<Hello_World_HelloReply>,
                 options: CallOptions,
-                _ body: @Sendable @escaping (ClientResponse.Single<Hello_World_Greeter.Method.SayHello.Output>) async throws -> R
+                _ body: @Sendable @escaping (ClientResponse.Single<Hello_World_HelloReply>) async throws -> R
             ) async throws -> R where R: Sendable
         }
 
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         extension Hello_World_Greeter.ClientProtocol {
             internal func sayHello<R>(
-                request: ClientRequest.Single<Hello_World_Greeter.Method.SayHello.Input>,
+                request: ClientRequest.Single<Hello_World_HelloRequest>,
                 options: CallOptions = .defaults,
-                _ body: @Sendable @escaping (ClientResponse.Single<Hello_World_Greeter.Method.SayHello.Output>) async throws -> R
+                _ body: @Sendable @escaping (ClientResponse.Single<Hello_World_HelloReply>) async throws -> R
             ) async throws -> R where R: Sendable {
                 try await self.sayHello(
                     request: request,
-                    serializer: ProtobufSerializer<Hello_World_Greeter.Method.SayHello.Input>(),
-                    deserializer: ProtobufDeserializer<Hello_World_Greeter.Method.SayHello.Output>(),
+                    serializer: ProtobufSerializer<Hello_World_HelloRequest>(),
+                    deserializer: ProtobufDeserializer<Hello_World_HelloReply>(),
                     options: options,
                     body
                 )
@@ -120,11 +120,11 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
             
             /// Sends a greeting.
             internal func sayHello<R>(
-                request: ClientRequest.Single<Hello_World_Greeter.Method.SayHello.Input>,
-                serializer: some MessageSerializer<Hello_World_Greeter.Method.SayHello.Input>,
-                deserializer: some MessageDeserializer<Hello_World_Greeter.Method.SayHello.Output>,
+                request: ClientRequest.Single<Hello_World_HelloRequest>,
+                serializer: some MessageSerializer<Hello_World_HelloRequest>,
+                deserializer: some MessageDeserializer<Hello_World_HelloReply>,
                 options: CallOptions = .defaults,
-                _ body: @Sendable @escaping (ClientResponse.Single<Hello_World_Greeter.Method.SayHello.Output>) async throws -> R
+                _ body: @Sendable @escaping (ClientResponse.Single<Hello_World_HelloReply>) async throws -> R
             ) async throws -> R where R: Sendable {
                 try await self.client.unary(
                     request: request,
@@ -198,7 +198,7 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         public protocol Helloworld_GreeterStreamingServiceProtocol: GRPCCore.RegistrableRPCService {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Stream<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld_Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Stream<Helloworld_HelloRequest>) async throws -> ServerResponse.Stream<Helloworld_HelloReply>
         }
 
         /// Conformance to `GRPCCore.RegistrableRPCService`.
@@ -208,8 +208,8 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
           public func registerMethods(with router: inout GRPCCore.RPCRouter) {
             router.registerHandler(
               forMethod: Helloworld_Greeter.Method.SayHello.descriptor,
-              deserializer: ProtobufDeserializer<Helloworld_Greeter.Method.SayHello.Input>(),
-              serializer: ProtobufSerializer<Helloworld_Greeter.Method.SayHello.Output>(),
+              deserializer: ProtobufDeserializer<Helloworld_HelloRequest>(),
+              serializer: ProtobufSerializer<Helloworld_HelloReply>(),
               handler: { request in
                 try await self.sayHello(request: request)
               }
@@ -221,13 +221,13 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         public protocol Helloworld_GreeterServiceProtocol: Helloworld_Greeter.StreamingServiceProtocol {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Single<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Single<Helloworld_Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Single<Helloworld_HelloRequest>) async throws -> ServerResponse.Single<Helloworld_HelloReply>
         }
 
         /// Partial conformance to `Helloworld_GreeterStreamingServiceProtocol`.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         extension Helloworld_Greeter.ServiceProtocol {
-          public func sayHello(request: ServerRequest.Stream<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld_Greeter.Method.SayHello.Output> {
+          public func sayHello(request: ServerRequest.Stream<Helloworld_HelloRequest>) async throws -> ServerResponse.Stream<Helloworld_HelloReply> {
             let response = try await self.sayHello(request: ServerRequest.Single(stream: request))
             return ServerResponse.Stream(single: response)
           }
@@ -297,7 +297,7 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         package protocol GreeterStreamingServiceProtocol: GRPCCore.RegistrableRPCService {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Stream<Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Stream<HelloRequest>) async throws -> ServerResponse.Stream<HelloReply>
         }
 
         /// Conformance to `GRPCCore.RegistrableRPCService`.
@@ -307,8 +307,8 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
           package func registerMethods(with router: inout GRPCCore.RPCRouter) {
             router.registerHandler(
               forMethod: Greeter.Method.SayHello.descriptor,
-              deserializer: ProtobufDeserializer<Greeter.Method.SayHello.Input>(),
-              serializer: ProtobufSerializer<Greeter.Method.SayHello.Output>(),
+              deserializer: ProtobufDeserializer<HelloRequest>(),
+              serializer: ProtobufSerializer<HelloReply>(),
               handler: { request in
                 try await self.sayHello(request: request)
               }
@@ -320,13 +320,13 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         package protocol GreeterServiceProtocol: Greeter.StreamingServiceProtocol {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Single<Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Single<Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Single<HelloRequest>) async throws -> ServerResponse.Single<HelloReply>
         }
 
         /// Partial conformance to `GreeterStreamingServiceProtocol`.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         extension Greeter.ServiceProtocol {
-          package func sayHello(request: ServerRequest.Stream<Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Greeter.Method.SayHello.Output> {
+          package func sayHello(request: ServerRequest.Stream<HelloRequest>) async throws -> ServerResponse.Stream<HelloReply> {
             let response = try await self.sayHello(request: ServerRequest.Single(stream: request))
             return ServerResponse.Stream(single: response)
           }
@@ -337,25 +337,25 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         package protocol GreeterClientProtocol: Sendable {
           /// Sends a greeting.
           func sayHello<R>(
-            request: ClientRequest.Single<Greeter.Method.SayHello.Input>,
-            serializer: some MessageSerializer<Greeter.Method.SayHello.Input>,
-            deserializer: some MessageDeserializer<Greeter.Method.SayHello.Output>,
+            request: ClientRequest.Single<HelloRequest>,
+            serializer: some MessageSerializer<HelloRequest>,
+            deserializer: some MessageDeserializer<HelloReply>,
             options: CallOptions,
-            _ body: @Sendable @escaping (ClientResponse.Single<Greeter.Method.SayHello.Output>) async throws -> R
+            _ body: @Sendable @escaping (ClientResponse.Single<HelloReply>) async throws -> R
           ) async throws -> R where R: Sendable
         }
 
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         extension Greeter.ClientProtocol {
           package func sayHello<R>(
-            request: ClientRequest.Single<Greeter.Method.SayHello.Input>,
+            request: ClientRequest.Single<HelloRequest>,
             options: CallOptions = .defaults,
-            _ body: @Sendable @escaping (ClientResponse.Single<Greeter.Method.SayHello.Output>) async throws -> R
+            _ body: @Sendable @escaping (ClientResponse.Single<HelloReply>) async throws -> R
           ) async throws -> R where R: Sendable {
             try await self.sayHello(
               request: request,
-              serializer: ProtobufSerializer<Greeter.Method.SayHello.Input>(),
-              deserializer: ProtobufDeserializer<Greeter.Method.SayHello.Output>(),
+              serializer: ProtobufSerializer<HelloRequest>(),
+              deserializer: ProtobufDeserializer<HelloReply>(),
               options: options,
               body
             )
@@ -373,11 +373,11 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
           
           /// Sends a greeting.
           package func sayHello<R>(
-            request: ClientRequest.Single<Greeter.Method.SayHello.Input>,
-            serializer: some MessageSerializer<Greeter.Method.SayHello.Input>,
-            deserializer: some MessageDeserializer<Greeter.Method.SayHello.Output>,
+            request: ClientRequest.Single<HelloRequest>,
+            serializer: some MessageSerializer<HelloRequest>,
+            deserializer: some MessageDeserializer<HelloReply>,
             options: CallOptions = .defaults,
-            _ body: @Sendable @escaping (ClientResponse.Single<Greeter.Method.SayHello.Output>) async throws -> R
+            _ body: @Sendable @escaping (ClientResponse.Single<HelloReply>) async throws -> R
           ) async throws -> R where R: Sendable {
             try await self.client.unary(
               request: request,