[native] Removing codegen-grpc from native

Summary:
This diff removes the codegen-grpc yarn command from the native. We are removed the C++ gRPC from the client and the compilation of the gRPC files will be handled by the cargo building process. Also, we are removing running this command from the documentation and shared folder because gRPC generation for the rest of the C++ codebase is done using the CMakeFile generation command.

Linear task: ENG-2276

Test Plan: Native builds are successfully passed.

Reviewers: jon, atul, varun, ashoat

Reviewed By: atul, ashoat

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D5714