Describe the enhancement requested

From apache/arrow-rs#5731 (comment)

Originally Flight RPC was implemented as a framework wrapping gRPC. This was especially expedient for the C++ implementation. By now it's mostly a weight dragging down Flight users, especially Flight SQL.

If we have the chance to evolve Flight SQL and/or Flight RPC, some changes may include:

• Use a proper gRPC service definition, instead of opaque bytes payloads
• [Format][FlightRPC] Transfer FlightData in pieces #34485
• [C++][FlightRPC] Memory tracking for arrow flight over grpc #37900

Component(s)

FlightRPC, Format