Story Form

As a Block Node Engineer
I want to use PBJ generated classes and avoid protoc generated classes
So that I have no dependencies on protoc and can remove that step from the build

Technical Notes

An earlier issue removed the protoc gRPC stubs and switched to PBJ stubs, but the refactor somehow switched everything back to protoc stubs. We would very much like to remove the protoc compile step from the build entirely so we don't have the dependency tree in the deployed system and also avoid accidentally importing the wrong version of protobuf-defined classes.