* Add initial event manager implementation,
roughly mimicking Nordic's API.
* Add `position_state_changed` and
`keycode_state_changed` events.
* Hook up HID and keymap to new events
instead of using behaviour global event
crazy.
* Refactor Kyria into separate left/right "revisions"
of the Kyria shield, and include central
kyria.dtsi file with common definition.
* Fixes for keymaps to work fully with matrix
transforms that override effective rows/columns.
* Add ability for matrix transform to do row/col
offsets, which is needed for split keyboards.
* 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.
* Allows "gaps" for keyboards like Kyra.
* Allows keyboards with matrixes that don't map the logical key
locations to have normal looking keymaps when defined.
