external plugins support

[Lexedia]

Description

A lavalink update in the big 2025???? Not on my watch liberal, i eat mint gum daily to keep my mouth clean and sweet, you should too. Colgate:tm:
Everytime i think about opemning a PR i think "Oh wow you're just writing shit on here" and you'd be correct, this would
be less fun without my shitpost though (we eating good).

_{Dont ask me why the git history is weird, that's fire though, who doesn't love conflicts???}

Type of change

• New feature (non-breaking change which adds functionality)

Checklist:

• Ran dart analyze or make analyze and fixed all issues
• Ran dart format --set-exit-if-changed -l 160 ./lib or make format and fixed all issues
• I have made corresponding changes to the documentation