Blender Git Loki

Fix T76481: Fast clicks over Dopesheet toggles trigger renaming

Making this work reliably on the event system side is difficult. So
instead, let the toggle icons take and swallow double-click events on
the UI handler level.

The second change in this patch seems to be only needed for touchpads.
Without it, renaming would still be triggered sometimes, because the
hovered button wasn't re-activated fast enough.