Mautrix

* *(client)* Added support for knocking on rooms (thanks to maltee1 in 105).
* *(bridge)* Added config option to set key rotation settings with e2be.

* *(bridge)* Updated e2be helper to stop bridge if syncing fails.
* *(util.async_db)* Updated asyncpg connector to stop program if an asyncpg `InternalClientError` is thrown. These errors usually cause everything to get stuck.
* The behavior can be disabled by passing `meow_exit_on_ice` = `false` in the `db_args`.

* *(util.formatter)* Added support for parsing `img` tags
* By default, the `alt` or `title` attribute will be used as plaintext.
* *(types)* Added `notifications` object to power level content class.
* *(bridge)* Added utility methods for handling incoming knocks in `MatrixHandler` (thanks to maltee1 in 103).
* *(appservice)* Updated `IntentAPI` to add the `fi.mau.double_puppet_source` to all state events sent with double puppeted intents (previously it was only added to non-state events).

* *(bridge)* Fixed double puppeting `start` method not handling some errors from /whoami correctly.
* *(types)* Added `com.beeper.message_send_status` event type for bridging status.

* *(bridge.commands)* Added `reason` field for `CommandEvent.redact`.
* *(client.api)* Added `reason` field for the `unban_user` method (thanks to maltee1 in 101).
* *(bridge)* Changed automatic DM portal creation to only apply when the invite event specifies `"is_direct": true` (thanks to maltee1 in 102).
* *(util.program)* Changed `Program` to use create and set an event loop explicitly instead of using `get_event_loop`.
* *(util.program)* Added optional `exit_code` parameter to `manual_stop`.
* *(util.manhole)* Removed usage of loop parameters to fix Python 3.10 compatibility.
* *(appservice.api)* Switched `IntentAPI.batch_send` method to use custom Event classes instead of the default ones (since some normal event fields aren't applicable when batch sending).

* *(types, bridge)* Dropped support for appservice login with unstable prefix.
* *(util.async_db)* Fixed some database start errors causing unnecessary noise in logs.
* *(bridge.commands)* Added helper method to redact bridge commands.