URLSessionHTTPClient with GRPC support

[aheze]

Currently the library only supports NIOHTTPClient if you're using GRPC:

let client = ProtocolClient(
    httpClient: NIOHTTPClient(host: host, port: port, timeout: 10),
    config: ProtocolClientConfig(
        host: host,
        networkProtocol: .grpc,
        codec: ProtoCodec()
    )
)

This makes the current streaming response stop when the app is backgrounded.

Is there any way to use URLSessionHTTPClient with GRPC? This is to take advantage of URLSessionConfiguration which supports continuing the task for a short while in the background.

Btw thanks for your work! Works smoothly and easy to set up 💪

[rebello95]

👋🏽 @aheze - the documentation notes that is not possible to use URLSession for gRPC because URLSession does not support/expose trailers. If URLSession exposes this in the future, we could support gRPC using that client 😃

There are a few threads online asking about using NIO in the background. If you'd like to explore that more, I recommend you file an issue in the NIO repository.