plugins.twitch: add access token to clips

[bastimeyer]

Resolves #3761

Clips require three different "persisted" GQL queries now (I couldn't make the previously used custom query work), one which fetches the access token and video qualities, one which fetches the broadcaster and category names, and one which fetches the clip title. There's another query called "ClipsSocialShare" which combines the second and third queries, but the result only includes the broadcaster's "login" property, and not the "displayName" property, which is not necessarily the same.

I am also not sure if there are clips where the validation could break, as it expects all data to be available, whereas the previous validation schema made the metadata optional.

$ streamlink -l debug --title '{author} - {category} - {title}' https://clips.twitch.tv/GrossRamshacklePheasantPipeHype-vb-LdFjwD-kLo87L best
[cli][debug] OS:         Linux-5.12.7-1-git-x86_64-with-glibc2.33
[cli][debug] Python:     3.9.5
[cli][debug] Streamlink: 2.1.2+11.gb7a05ed
[cli][debug] Requests(2.25.0), Socks(1.7.1), Websocket(0.58.0)
[cli][debug] Arguments:
[cli][debug]  url=https://clips.twitch.tv/GrossRamshacklePheasantPipeHype-vb-LdFjwD-kLo87L
[cli][debug]  stream=['best']
[cli][debug]  --loglevel=debug
[cli][debug]  --player=mpv
[cli][debug]  --player-args=--cache=yes --demuxer-max-bytes=750k --demuxer-max-back-bytes=2G
[cli][debug]  --title={author} - {category} - {title}
[cli][debug]  --hls-live-edge=2
[cli][debug]  --hls-segment-threads=2
[cli][debug]  --twitch-disable-hosting=True
[cli][debug]  --twitch-disable-ads=True
[cli][debug]  --twitch-disable-reruns=True
[cli][debug]  --twitch-low-latency=True
[cli][info] Found matching plugin twitch for URL https://clips.twitch.tv/GrossRamshacklePheasantPipeHype-vb-LdFjwD-kLo87L
[cli][info] Available streams: 360p30 (worst), 480p30, 720p60, 1080p60 (best)
[cli][info] Opening stream: 1080p60 (http)
[cli][debug] Pre-buffering 8192 bytes
[cli][info] Starting player: mpv
[cli.output][debug] Opening subprocess: mpv "--force-media-title=ludwig - Just Chatting - xQc admits to being a Tier 3 Pokimane sub." --cache=yes --demuxer-max-bytes=750k --demuxer-max-back-bytes=2G -
[cli][debug] Writing stream to output
[cli][info] Player closed
[cli][info] Stream ended
[cli][info] Closing currently open stream...

[gravyboat]

Looks good to me. Bummer about not being able to use a single query but that is Twitch's fault, not ours.