[CDJ-3000] Press-and-drag to reorder tracks in the tag list

It would be nice to be able to manually reorder tracks inside the tag list:

Core feature:

- Pressing-and-holding a track unlocks the focused track and allows it to be re-ordered by dragging your finger up/down
- Dragging the track to a new position and releasing confirms the track's new index in the tag list

Additional Thoughts:

- Dragging the track over another track displays a top or bottom border on the track being hovered (depending on if the finger is closer to the top or bottom of the hovered track). The border indicates the insertion point.
- The user can drag the focused track outside of the list to cancel moving the track, retaining its current index