* stricter youtubedl format selectors
make sure selectors avoid av1, and otherwise match as closely to the
maximum resolution enabled for transcoding
* add support for merge formats in youtubedl
* avoid vp9.2 in youtubedl to avoid any HDR
* move getEnabledResolutions, safer replace of imported extension
* add test for youtube-dl selectors
* Add server plugin filter hooks for import with torrent and url
* WIP: pre and post-import filter hooks
* Rebased
* Cleanup filters to accept imports
Co-authored-by: Chocobozzz <me@florianbigard.com>