[Audius] Add new extractor

[qulaz]

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What is the purpose of your pull request?

• Bug fix
• Improvement
• New extractor
• New feature

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Description of your pull request and other information

Add an extractor for Audius, a music streaming and sharing platform (like SoundCloud). Also this was requested in #24216

[dstftw]

Read coding conventions.

[qulaz]

I fixed all the code style issues I could see.

But i need help. Since first commit Audius changed a little bit. Audius is decentralized platform and they has multiple API hosts the list of which can be obtained using a special REST endpoint. Point is that before this list looked something like this:

https://discoveryprovider1.audius.co
https://discoveryprovider2.audius.co
...

But now it's looks something like this:

https://audius-metadata-2.figment.io
https://discoveryprovider.audius2.prod-us-west-2.staked.cloud
https://audius-dp.johannesburg.creatorseed.com
https://discovery-au-01.audius.openplayer.org
https://dn-jpn.audius.metadata.fyi
https://audius-disco.ams-x01.nl.supercache.org
https://audius-discovery.nz.modulational.com
...

The problem is that I have no idea how handle all of this different hosts with regexp. For now, as a temporary solution, i used .+/v1/tracks regexp, but then this extractor will triggered to links like https://super-random-host.com/v1/tracks/trackID. For now such links do not overlap with other extractors, but who knows what will happen next.