ToDo: change hover type dropdown into a checkbox "video preview"

[clsid2]

Some people are currently struggling to find the video preview option. Better to make it into a checkbox so it is more obvious.

[adipose]

What if we just made it the default?

[clsid2]

For a few users the preview graph causes a delay when closing the file. I want to investigate that further before enabling it by default.

[adipose]

Maybe the word "hover" could be replaced with "preview," and the dropdown could say "video/seek time." Not sure if that's an improvement.

[clsid2]

[ ] Show video preview
[ ] Show time     [Dropdown: Below/Above seekbar]

When checking Show video video grey out and check show time (as preview always includes time). If both unchecked then grey out the dropdown.

[adipose]

https://github.com/clsid2/mpc-hc/pull/3095