Add some (maybe) useful utilities for protobuf

[TeoGiane]

Summary

1. Fix wrong protobuf include directories, link libraries and protoc executable. We now explicitly use the version we locally install during configuration.
2. Add the cmake/ProtobufUtils.cmake file, which contains a cmake function that encapsulates the previous code we adopted to generate cpp and python files from the proto messages.

[brunoguindani]

Looks good, thanks! 😊

[mberaha]

Looks good to me! Thanks for the effort :)