feat: `/music skip` command

[tomassasovsky]

Description

We currently support playing YouTube playlists. Playing these enqueues all of the songs in that playlist.

Requirements

• Add songs to the queue instead of overriding the current song playing with the /music play command.
• Skip the current song playing with a new /music skip command. If no more tracks are in the queue, it will just stop playing the current song and leave the voice channel.