2024.06.19.0

add functionality to seek to the nearest chapter on click

settings: fix extremely bad cache bar defaults

I think this has been broken since the cache bar was split into
foreground and background components (and I had a bad half-height
cache bar in the defaults even before that for some insane reason). I
think these changes provide a much more reasonable out-of-the-box
experience (what can I say, they match my local configuration now).

ProgressBarCache: fix full bar drawing

HoverTime: fix redraw problem across unknown duration

When duration went to 0 and then came back with the same value it had
previously (e.g. playing the same video twice in a row), the time
would change to ???? and not change back to a timestamp until the
mouse was moved. This happened because the computed hover timestamp
did not get updated during the portion of unknown duration, so the
value was cached too aggressively.

By decoupling the positioning logic from the timestamp logic, the
intent becomes more obvious and hopefully less bug-prone.

HoverTime: redraw when duration changes

This was a bit of an oversight on how this was redrawn previously. For
example changing between two videos with the same resolution but
different duration, the time hovered would not update until the mouse
moved.

In theory it's possible for the duration to change while a video is
playing I guess (but normally this would be for streamed video, for
which we don't present the hover time at all) so that's another edge
case potentially handled.