effects: Improve animation durations and easing curves in Windowheap-based effects

This commit doubles the animation durations for WindowHeap-based effects
(Overview, Present Windows, and Desktop Grid) and uses the OutCubic easing
curve for their opening and closing animations. This makes them feel smoother
and more comfortable.

BUG: 455521
BUG: 448538
FIXED-IN: 5.26