Compile state service stubs

8. I would propose to not include ```state_service_pb2_grpc.py``` and ```state_service_pb2.py``` in git (it is like including compiled executions). We need to compile them in ```setup.py``` like we do it in ```snet-cli``` and ```snet-daemon```

_Originally posted by @astroseger in https://github.com/singnet/snet-sdk-python/pull/5#issuecomment-467867412_