[SBS] Add full support for all libraries in CMake

* File 'dependencies.cmake' is updated to configure and fully support Mxgui, Eigen, {fmt} and local libraries.

* Library {fmt} now works with every board, as it is no longer compiled with hardcoded flags.

* Function 'sbs_link_mxgui' is added, allowing to link Mxgui without respecifying the board.