* Basic Clueboard Californai Macropad shield definition.
* New "direct" KSCAN driver that supports non-matrix direct
wiring for switches, needed for macropad that doesn't have
a matrix at all.
* Some renames for existing KSCAN GPIO driver to make the implied
"matrix" part explicit.
* Use extra comptible = "zmk,behavior-global" to add
behaviors to global bindings for event notification.
* Implement mod-tap, as a keymap binding and global one
to skip tap if other keycode pressed while held.
