envmanager: Handle SSD toggling with kwin rules

Replace the convergentwindows KWin script SSD toggling with KWin rules to ensure windows are maximized and have no window border (and toggle off for docked mode). KWin rules work immediately at window creation, which is more efficient than listening to window creation events and manually changing properties on them.

Currently, window rules setting maximization don't seem to address all cases where a window gets unmaximized, so for the time being we will still need the logic in convergentwindows to handle any sidecases.