Add oauth support for audio cog

### What component of Red (cog, command, API) would you like to see improvements on?

Audio

### Describe the enhancement you're suggesting.

Right now, the only way to set up YouTube OAuth is to switch to an unmanaged node. However, this could be added as a feature in the Audio cog.

Here’s how I see it:
`!llset config oauth // Toggles OAuth login`
When enabled, the managed node is stopped and restarted with updated application.yml parameters, setting oauth.enabled: true.
Lavalink outputs an OAuth link and code to stdout, which can be parsed and sent to the owner's DMs.
After logging in, the refresh token must be extracted (from stdout), saved, and used to update application.yml. When !llset config oauth is toggled off, the refresh token is reset, requiring the OAuth setup process to be repeated.

### Anything else?

_No response_