* 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.
* 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.
