Protube skip forward/ backward button

@jonapatig (https://github.com/saproto/saproto/issues/2240)
> Hello beheer <3. I want a feature where protube admins are able to skip forward or backward through a song (+1 and -1 minute per click or so). This is coming from the frustration of playing a longer song/ set and it restarting from only the beginning and then having to listen to everything again :(.