* Add back in profiles, not using Zephyr
BT identity infrastructure.
* Restore additional `&bt` commands for profile
operations.
* Fix for split pairing and subscriptions, since
Zephyr persists subscriptions across connects.
* Remove keymap from peripheral builds, reduces
firmware size, and avoids unneeded attempts
to send HID data.
* Simplify the `bt` behavior to one current command
`BT_CLEAR_BONDS_CMD`.
* Simplify BLE code for split and non-split keyboards.
* Remove keymap processing from split peripheral side.
* Add `bt` behavior that can be used to perform certain actions,
such as next/prev identity, reset identity, etc.
NOTE: Multiple identities is only supported for non-split shields,
due to missing Zephyr identity functionality for dual
central/peripheral devices.
* Proper bond reset tied to action, that honors peripheral bonds,
so folks can reset and pair to other hosts, without breaking
bonds between splt halves.
* Track active mods when mods or keycode
events occur.
* Use the tracked mods when releasing or
generating keycode events.
* Track pending/used status in one array, for
improved storage efficency.
* 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.
* 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.
