Provide a maliput_cmake repo for cmake macros

[francocipollone]

Summary

Nowadays, for each package/repo we have a cmake folder where a couple of CMake files are included from the root CMake file.
This is causing duplication of code and it is prone to have different configurations among all the packages.

Proposal

Create a maliput_cmake for allocating CMake macros use along all the maliput repositories.

Also:

• Verify the flags for the C++ compiler: We might want to be stricter.