ProtocolClient.send breaks async stacktraces

The following implementation:
https://github.com/microsoft/vscode-debugadapter-node/blob/1621133e71527d9d46438edb766eaf8e731b68f5/testSupport/src/protocolClient.ts#L69-L80
is not async itself and returns the promise immediately without awaiting it. Consequently, if the promise gets rejected with an error, the stack trace in the error does not include either send or its caller. This unnecessarily complicates debugging of e.g. async unit tests that await send() and receive an unexpected error response.

Instead, the callback for doSend should capture the raw response in a wrapper promise, and then send should await that promise and translate it to a throw.

Comienza en testSupport/src/protocolClient.ts, en la implementación enlazada de ProtocolClient.send, e inspecciona cómo llama a doSend. Sigue la ruta de la promesa rechazada y verifica que send espera un wrapper alrededor de la respuesta sin procesar antes de traducir el error. Está hecho cuando los stack traces de rechazo asíncrono incluyen send y su llamador.