[Suggestion] Prioritize submitted songs when using autoplay

[Infinitay]

I noticed that if a user adds a song to the queue when they are also using /autoplay that it'll append the song. I think it would be better to change this behavior such that user-submitted tracks will be played before the auto-play suggestions.

I'd like to mention that I'm not sure if Fairqueue does this suggested behavior by submitting auto-play songs as a autoplay requester and therefore another user's submission will take priority.