Add ability to specify gRPC server/worker ports

My development setup is all Docker-based and I work inside a Docker container for development. From this docker environment, i'd love to be able to run a pipeline with a custom container image for local testing. I've been able to launch a sister beam docker container from my main docker container, but am running into an issue with the ports.

It would be really helpful if I could set a value for the control_address and logging_endpoint of the GrpcServer for the portable runner worker.

The 'docker run' command passes in a control_address here which ultimately comes from here. Similarly, the logging_endpoint passed in  here comes from here.

This would be a pretty small change, just exposing some knob to configure those endpoints rather than having them chosen by the gRPC server. Thanks!!