Mautrix

* *(bridge)* Fixed accidentally broken Python 3.7 compatibility.

* *(client.api)* Added `reason` field to `leave_room` and `invite_user` methods.

* *(util.formatter)* Deprecated the lxml-based HTML parser and made the htmlparser-based parser the default. The lxml-based parser will be removed in v0.15.
* *(client.api)* Fixed `filter_json` parameter in `get_messages` not being sent to the server correctly.
* *(bridge)* Added utilities for implementing disappearing messages.

* *(client)* Fixed error inviting users with custom member event content if the server had disabled fetching profiles.
* *(util.utf16_surrogate)* Added utilities for adding/removing unicode surrogate pairs in strings.
* *(util.magic)* Added check to make sure the parameter to `mimetype()` is either `bytes` or `str`.

* **Breaking change *(util.message_send_checkpoint)*** Changed order of `send` parameters to match `BridgeState.send` (this is not used by most software, which is why the breaking change is in a patch release).
* *(util.async_db)* Changed the default size of the aiosqlite thread pool to 1, as it doesn't reliably work with higher values.
* *(util.async_db)* Added logging for database queries that take a long time (>1 second).
* *(client)* Added logging for sync requests that take a long time (>40 seconds, with the timeout being 30 seconds).
* *(util.variation_selector)* Fixed variation selectors being incorrectly added even if the emoji had a skin tone selector.
* *(bridge)* Fixed the process getting stuck if a config error caused the bridge to stop itself without stopping the SQLite thread.
* Added pre-commit hooks to run black, isort and some other checks.

* *(util.formatter)* Removed the default handler for room pill conversion.
* This means they'll be formatted as normal links unless the bridge or other thing using the formatter overrides `room_pill_to_fstring`.
* *(types)* Fixed the `event_id` property of `MatrixURI`s throwing an error (instead of returning `None`) when the parsed link didn't contain a second part with an event ID.