Nightly: A mostly finished refactor of TPGSettings objects
- Refactored TPGSettings so it links to the FreeCAD Document data types for storage
- TPGSettings are now saved and loaded from the FreeCAD document file.

Remaining:
- Fixing Python TPG's TPGSettings so they display on the CamProjectDockWindow.
- Refactor Python TPG's TPGSettings objects so they match the C++ ones.
- Make Radio buttons store value in Document objects immediately after change