Add YouTube PO token & IP rotation

[MichailiK]

This pull request...

• Fixes a bug
• Introduces a new feature
• Improves an existing feature
• Boosts code quality or performance

Description

• Adds config options to provide a PO token & visitor data. Omitting these makes it obvious to YouTube you're a bot & can easily lead to an IP ban.
• Adds IP(v6) rotation in the hopes of reducing chances of getting IP bans.

Unfortunately the setup for both are fairly complicated. I'm hoping that obtaining a PO token bit can be automated (thus this being a draft PR). IPv6 rotation is even more complicated & hosting-dependent, so this is probably reserved for power users.

Purpose

Allows for (semi-)reliable YouTube playback again

Relevant Issue(s)

Somewhat fixes #1588

Somewhat fixes #1682

TODO

• Document or automate PO token retrieval.
  • Lavalink's youtube-source README suggests to run the youtube-trusted-session-generator python script/docker image to generate these.
  • Alternatively, yt-dlp's wiki has a guide on manually retrieving PO tokens
    • In step 6, instead of exporting cookies, I believe you can extract the visitor id in the player request at context.client.visitorData, im not sure if its the identical though i have to yet double check.
    • In step 7, instead of using yt-dlp you put the PO token & visitor data in the config.txt, of course
• Document IPv6 rotation.
  • Lavalink's RoutePlanner and IPv6 docs pages are a great reference for this.
• Some cleanup & fixing inconsistencies

[AndrewBrough]

For anyone wondering, I was able to build this using jdk-21 and maven on a windows machine - and it worked, all I had to do was drop the target/JMusicBot-All.jre in place of the 0.4.3 version and double click and it worked. Playing music right now in my server.

Should be simple to make the pipelines pass. Small refactor to reduce complexity of your added ip functionality and we'd be good to make a new tag, I'd think.

If I don't see any progress here in a week I'll fork and tag a release.

Update: I made a release you use until this repo is resolved.
https://github.com/AndrewBrough/MusicBotButItWorksIn2025/releases/tag/1.0