Limit the length of a song

[TomCan]

Prevent adding songs that are too long (eg 10 minutes, configurable)

[borisson]

Instead of doing this on the bot-side, we could do this on the website.

If a song is longer then 15 minutes, play it until that mark, then skip and go to the next one, unless there are no songs in the queue. With an empty queue we should play the entire song.