Swap/Move Queue

A feature that can move or swap items in the queue to other positions
For example:
- `/swap 1 2` will swap songs in position 1 and 2 in queue, and
- `/move 1 3` will move 1 to position 3, making song 2 now song 1 in queue, and song 3 now song 2 in queue.

Tasks (like amongus)
- [ ] Swap command
- [ ] Move command