Refractor IncludePathResolver out into 2 parts.

First part is the MakeFileResolver and the second one is
CustomIncludePaths for out of project files.
WIP.
Make the AddCustomIncludePathAction work once again.
Added unit tests.
const& the code. Don't inline functions.
Split the IncludePathResolver into MakeFileResolver and NoProjectIncludePathsManager

REVIEW: 119057