* Add IS_LAYER_ON_STATE()/IS_LAYER_OFF_STATE() macros
* Add docs for IS_LAYER_ON/OFF(_STATE) macros
* Remove IS_LAYER_ON/OFF_STATE redefinition in userspace
* Run clang-format on quantum/quantum.h
* Redefine IS_LAYER_ON/OFF(_STATE) as aliases of existing layer functions
Also update relevant doc entries.
Needs testing to check if this breaks existing IS_LAYER_ON/OFF usage in certain
edge cases (namely calling the macros with 0).
* Reformat layer check function docs