effects/overview: Animate if the thumbnail is dropped in an heap
If the new position the thumbnail was dropped intersects the geometry of an heap in any way, then execute the animation, otherwise skip it (the case of drop on a desktop thumbnails in the overview) previous patch attempted that but with not completely correct logic
(cherry picked from commit 0e9f1e72)
0e9f1e72 effects/overview: Animate if the thumbnail is dropped in an heap
Co-authored-by: Marco Martin notmart@gmail.com