isVisibleForInteraction: fails to discover an overlay window

There seems to be an issue, where `isVisibleForInteraction:` returns `YES` despite there being a `UIWindow` instance that should take the touch of the user, rather than it reaching the element.

In addition to its current logic, the method should check first if there are other windows **visible and answering `hitTest:withEvent:` with a non-nil value**; if so, it should fail the interaction visibility check.