Support binary logging of wire protocol data

[tweidema]

Describe the solution you'd like

In Release 2.x I would like to see support for binary logging, maybe based on https://github.com/grpc/grpc/blob/master/doc/binary-logging.md . Should include both message- and meta-data.
My use-case is a low-overhead, but complete log of traffic server-side, to/from clients, primarily for use in supportcases. Logging the binary protocol data should be low-overhead in the call-path and take up less storage (as opposed to logging deserialized/parsed messages), and it doesn't matter (to me) if it then takes time to search/parse the data when there is a need for it.
Another usecase would be documenting/replaying integration testruns.
I've looked in the source-code, and Sources/GRPCCore/Call/Server/Internal/ServerRPCExecutor.swift seems to be the place for it, at least for incoming traffic.

Describe alternatives you've considered

Logging deserialized/parsed data from single methods or from a serverInterceptor if possible.