player: improve seek
This MR improves seek:
- UI feedback when seeking: The seeked time is now updated immediately (and won't go to the previous position)
- The Relative seek now use the player timer absolute position instead of the demux time (fix -2sec seek when seeking -3sec and +4sec seek when seeking +3sec)
- Moved navigation handling inside the player (in was needed for the relative seek)
Sorry for the sample (but it takes a long time to seek, so good for the example).
Before this MR (no feedback at all):
Screencast_from_2023-02-20_13-48-35
After this MR (you know where you are going):
Edited by Thomas Guillem