Adds new functionality and a behavior to disconnect an active BLE connection.
The motivation for this is that for some devices like phones, the presence of an
active BLE connection results in the onscreen keyboard being selected.
* New ZMK_SLEEP Kconfig symbol to enable the functionality.
* Switch to PORT events that allows wake from deep sleep.
* Initial basic power management policy, with idle ms,
and ignoring deep sleep if we detect a USB connection.
* 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.
