Github action for protobuf

[Theodore Omtzigt]

I have a CMake based C++ project that needs to support protocol buffers across Windows, Linux, and MacOS. We are using Github actions to regress any pushes and PRs, and I am looking for the best approach to a include protobuf in the Github Actions framework. 

Some of the dependent projects need the protobuf environment to be installed as they are using CMake's find_package() to configure themselves. The fact that each environment uses a different build process is causing me grief. Looking for guidance how to construct a Github action to include protobuf in a CMake project.