Buttons for navigation on the Timeline:
- Prev Marker: Jump to the previous marker.
- Add Marker: Create a new Marker and open the marker name prompt.
- Next Marker: Jump to the next marker.
- Prev Second: Go back by 1 second.
- Previous 1/4: Go back by 1/4 of a second.
- Snap to Second: Jump to the nearest second.
- Next 1/4: Go forward by 1/4 of a second.
- Next Second: Go forward by 1 second.
