Previously, we were considering the mouse to be "out" of a div when its
hitbox wasn't hovered. However, if a parent listened for
"mouse_down_out" and a child occluded the parent, the parent would
always think the mouse was out even when the user clicked the child.
This commit changes the definition of "mouse out" to simply mean "does
not contain the point", without accounting for occlusion.
Release Notes:
- N/A
Co-authored-by: Julia <julia@zed.dev>
