Close windows with Super+Middle/Three-finger click

As it is already possible to move windows with **super + left click** and resize them with **super + right click**, a logical addition to this behavior would be to close windows with **super + middle/three-finger click**.

**Initial Post:**

> As it is already possible to move windows with **super + left click** and resize them with **super + right click**, a logical addition to this behavior would be to raise and lower windows with **super + middle click**.

> In this way a **super + middle click** would raise windows which are not on top, and lower windows which are already on top. Moreover the middle click should lower the window by only one level, so that is possible switch fast between two windows, even if there are others in the background. To cycle between different levels the **super + mouse wheel** could be used.

> Also a **super + middle click** should lower all windows which overlap with the raised window. This would be important when dealing with two tiled windows in front of a maximized window. A **super + middle click** on one of the tiled windows should lower both, because both overlap with the maximized window. Otherwise a second click (left click or middle click) on the maximized window would be needed to bring it to front entirely.

> A similar feature (with different behavior) is already in KDE Plasma.