Fix perf benchmarks (#948)

Motivation:

In #922 we adopted some changes from NIO HTTP/2: our handlers now speak
in terms of `HTTP2Frame.FramePayload` rather than `HTTP2Frame`. We
forgot to update our benchmarks at that time.

Modifications:

- Speak in `HTTP2Frame.FramePayload`s in embedded client benchmarks
- Fix up a couple of typos in benchmark names

Result:

Benchmarks work.

Sources/GRPCPerformanceTests/Benchmarks/EmbeddedClientThroughput.swift

@@ -102,7 +102,7 @@ class EmbeddedClientThroughput: Benchmark {
 
       // Read out the request frames.
       var requestFrames = 0
-      while let _ = try channel.readOutbound(as: HTTP2Frame.self) {
+      while let _ = try channel.readOutbound(as: HTTP2Frame.FramePayload.self) {
         requestFrames += 1
       }
       precondition(requestFrames == 3) // headers, data, empty data (end-stream)
@@ -114,15 +114,13 @@ class EmbeddedClientThroughput: Benchmark {
         ":status": "200",
         "content-type": "application/grpc+proto",
       ]
-      let headerFrame = HTTP2Frame(
-        streamID: .init(1),
-        payload: .headers(.init(headers: responseHeaders))
-      )
+
+      let headerFrame = HTTP2Frame.FramePayload.headers(.init(headers: responseHeaders))
       try channel.writeInbound(headerFrame)
 
       // The response data.
       for chunk in self.responseDataChunks {
-        let frame = HTTP2Frame(streamID: 1, payload: .data(.init(data: .byteBuffer(chunk))))
+        let frame = HTTP2Frame.FramePayload.data(.init(data: .byteBuffer(chunk)))
         try channel.writeInbound(frame)
       }
 
@@ -131,10 +129,7 @@ class EmbeddedClientThroughput: Benchmark {
         "grpc-status": "0",
         "grpc-message": "ok",
       ]
-      let trailersFrame = HTTP2Frame(
-        streamID: .init(1),
-        payload: .headers(.init(headers: responseTrailers))
-      )
+      let trailersFrame = HTTP2Frame.FramePayload.headers(.init(headers: responseTrailers))
       try channel.writeInbound(trailersFrame)
 
       // And read them back out.

Sources/GRPCPerformanceTests/main.swift

@@ -63,13 +63,13 @@ func runBenchmarks(spec: TestSpec) {
   )
 
   measureAndPrint(
-    description: "embedded_client_unary_10k_large_requests",
+    description: "embedded_client_unary_1k_large_requests",
     benchmark: EmbeddedClientThroughput(requests: 1000, text: largeRequest),
     spec: spec
   )
 
   measureAndPrint(
-    description: "embedded_client_unary_10k_large_requests_1k_frames",
+    description: "embedded_client_unary_1k_large_requests_1k_frames",
     benchmark: EmbeddedClientThroughput(
       requests: 1000,
       text: largeRequest,