Initial 0.10.x release

This release:
- Exposes a number of Seen media in media groups
- Exposes playlists duration
- Adds filtering playlists by the type of media they contain
- Allows to sort albums by their import date
- Allows to sort artists by number of albums & last playback date

It also fixes some potential deadlocks and other bugs.

See https://code.videolan.org/videolan/medialibrary/-/milestones/5 for
the full list of issues & merge requests associated with this version.
This tag has no release notes.