Seeking consistency and fixes

[pannal]

GHI (If applicable): #

Description:

• don't auto-apply current seek when pressing down on the seekbar (when auto seek is enabled)
• properly reset seek states to avoid issues when switching qualities

Checklist:

• [x] I have based this PR against the develop branch

[ruuk]

I'm noticing some weird behavior with seeking. If you are seeking around the bright orange bar follows the seeking position properly, but if you move to the left of the current playback time (dark orange bar) it seems like the it switches to using dark orange for seeking and the bright orange for current position. The bright orange should always be for seeking, the dark orange should always show the current video position and not move or change until after a seek, this includes when using the 'dots'. This also seems to be in develop, but I'm pretty sure was introduces with one of the earlier seeking changes.

[pannal]

OK, I've made the following changes:

• the seek indicator now overlays the progress indicator at all times
• when seeking negatively, the seek indicator doesn't expand negatively from the current position, but indicates the seek in a more traditional way, starting from position 0
• I've adjusted the height and vertical position of the seek indicator to be the same as the position indicator, because it now properly overlays and expands