Detailed board model for phase-2
Changes for first version of phase-2 plugins with support for most core features, in particular:
- Detailed model of board - service module, processor, processor subcomponents & optical modules
- CMake: Added modules that implement utility functions that add targets for: RPM packaging, clang-format, and doxygen.
- CI: Common xarch build pipeline, incl. doxygen & YUM repo jobs, customised with variables
- Used by this repo and by downstream repos