[Lily/Video] add m3u8 support

[jexjws]

1. using hls.js to play m3u8
2. bundled hls.js directly into the extension

[jexjws]

if (!(await Scratch.canFetch(url))) return;

WARNING : If the resource URLs in a .m3u8 file are not on the same domain as the .m3u8 file itself, the client can fetch resources from other domains without using Scratch.fetch.

[CubesterYT]

If you use an outside library, you must make an offline copy of it and imbibe it into the extension directly, and include the license of said library in the extension as well.

[jexjws]

make an offline copy of it and imbibe it into the extension directly

1. Why would we bundle hls.js directly into the extension? It seems unnecessary to add a 400KB overhead for handling non-M3U8 videos. Is this intended for offline usage?

2. if we do this, when the upstream project releases important updates (such as security updates), we will need to manually update the hls.js within our repository. Manual updates can cause delays. Is there a way to solve this problem (for example, by having Dependabot manage the hls.js within extensions repository? I'm not familiar with Dependabot and wouldn't know how to set that up.)

and include the license of said library in the extension as well.

OK. I will do this.

[LilyMakesThings]

1. It's intended for offline usage and in the unlikely event it becomes inaccessible for whatever reason.
2. If it works, what reason would there be to update in a timely manner? You'd be amazed how many dependencies for Scratch and by extension TurboWarp have not been updated in half a decade.

[jexjws]

Addressed. Please review the changes.