Add subscene integration

[shellawa]

Barely got it to work, but I added a subscene panel in the subtitle menu, where you can find subtitles there and add them directly to the playing video without having to leave the app. I never actually do frontend stuff before, so I just put random css in and hoping for the best. Also there are still issues I found, listed here:

• [ ] Select OFF if there isn't any subtitle available
• [ ] Using arrow buttons in textboxes doesn't work correctly
• [ ] Bad ui
• [ ] Websecurity is disabled because my dumbself doesn't know how to bypass cors
• [ ] There are many desync subtitles on subscene, idk how to advance them (delaying works fine)
• [ ] There isn't a way to prefer the selected language

[ThaUnknown]

ignoring the fact that the code is.... bad...., I'm not interested in this

this adds an extra dependency to Miru, this comes with a lot of issues down the line, subs will become depended on a 3rd party service, have issues with "hey these subs are wrong", or "this episode is wrong", or "this show isn't" correct

Miru already depends on AniList, AniZip and Tosho, if one of those goes down, Miru stops, I don't want another dependency in the mix

Many subs in subscene will come from torrents anyways, so the user can simply pick a different torrent that has these subtitles