Merge pulumi/pulumi#11085

11085: Add debug GRPC interceptors that print conversations in JSON r=t0yv0 a=t0yv0

<!--- 
Thanks so much for your contribution! If this is your first time contributing, please ensure that you have read the [CONTRIBUTING](https://github.com/pulumi/pulumi/blob/master/CONTRIBUTING.md) documentation.
-->

# Description

<!--- Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. -->

Fixes pulumi/pulumi#10232

`PULUMI_DEBUG_GRPC=./debug.json pulumi preview` now works.

The debug APIs are probably unstable so I moved them out to their own repo rather than hosting under sdk/.

Debug interceptors are no-op unless the process initializes them in main. Currently only `pulumi` process initializes them if the env var is set. This way we observe conversations only once, as a server for ResourceMonitor etc, and as a client for plugin conversations (language and resource).

I can now see provider conversations logged which was of interest to me.


## Checklist

<!--- Please provide details if the checkbox below is to be left unchecked. -->
- [ ] I have added tests that prove my fix is effective or that my feature works
<!--- 
User-facing changes require a CHANGELOG entry.
-->
- [ ] I have run `make changelog` and committed the `changelog/pending/<file>` documenting my change
<!--
If the change(s) in this PR is a modification of an existing call to the Pulumi Service,
then the service should honor older versions of the CLI where this change would not exist.
You must then bump the API version in /pkg/backend/httpstate/client/api.go, as well as add
it to the service.
-->
- [ ] Yes, there are changes in this PR that warrants bumping the Pulumi Service API version
  <!-- `@Pulumi` employees: If yes, you must submit corresponding changes in the service repo. -->


Co-authored-by: Anton Tayanovskyy <anton.tayanovskyy@gmail.com>

pulumi-language-dotnet/main.go

@@ -106,22 +106,24 @@ func main() {
 	}
 
 	// Fire up a gRPC server, letting the kernel choose a free port.
-	port, done, err := rpcutil.Serve(0, cancelChannel, []func(*grpc.Server) error{
-		func(srv *grpc.Server) error {
+	handle, err := rpcutil.ServeWithOptions(rpcutil.ServeOptions{
+		Cancel: cancelChannel,
+		Init: func(srv *grpc.Server) error {
 			host := newLanguageHost(dotnetExec, engineAddress, tracing, binary)
 			pulumirpc.RegisterLanguageRuntimeServer(srv, host)
 			return nil
 		},
-	}, nil)
+		Options: rpcutil.OpenTracingServerInterceptorOptions(nil),
+	})
 	if err != nil {
 		cmdutil.Exit(errors.Wrapf(err, "could not start language host RPC server"))
 	}
 
 	// Otherwise, print out the port so that the spawner knows how to reach us.
-	fmt.Printf("%d\n", port)
+	fmt.Printf("%d\n", handle.Port)
 
 	// And finally wait for the server to stop serving.
-	if err := <-done; err != nil {
+	if err := <-handle.Done; err != nil {
 		cmdutil.Exit(errors.Wrapf(err, "language host RPC stopped serving"))
 	}
 }