Better Format Sorting (Squashed)

Better Format Sorting (Squashed)

* Added --format-sort (-S height,filesize)
* Made fields reversible (-S +height)
* Added --format-sort-force, --no-format-sort-force
* Added limit (-S height:720)
* Added codec preference (-S vcodec,acodec)
* Correct handling of preference<-1000

* Rebased to yt-dlc
* Automatically determine missing bitrates
* aext, vext, protocol, acodec, vcodec can now takes priority as string, not number (-S vext:webm)
* Correct handling of None in codec, audio_codec (None means the codec is unknown while 'none' means it doesn't exist)
* Correctly parse filesize (-S filesize:200M)
* Generalized preference calculation

* Rewrote entire code into the class FormatSort
* Correctly handle user input errors
* Combined fields (-S +ext:webm:webm)
* Closest mode (-S filesize~50M)
* Aliases (framerate=fps, br=bitrate etc)

* Documentation