Add more functionality (no cq integration yet) and add a dummy test

Makefile

build.yaml

src/cpp/rpcmanager/grpc_rpc_manager.cc

src/cpp/rpcmanager/grpc_rpc_manager.h

test/cpp/rpcmanager/grpc_rpc_manager_test.cc

test/cpp/rpcmanager/grpc_rpc_manager_test.h

tools/run_tests/sources_and_headers.json

tools/run_tests/tests.json

.../test/grpc_rpc_manager_test/grpc_rpc_manager_test.vcxproj

...pc_rpc_manager_test/grpc_rpc_manager_test.vcxproj.filters