A new unified widget to see and edit Night Color times. Visual instead of purely text-based.
Make sure it works in RTL mode. Right now there are some calculations in
HandleOnlySliderwhich appear to be LTR-assuming.
Implement some of the remaining constraints from old TimeField code, like max 700 min transition time, non-overlap, etc.
Make dragging increment in steps of 1 or 5, not 3