Fix size restore upon keyboard close in XdgSurfaceClient
in XdgSurfaceClient setFrameGeometry is async, so we can't rely on it having the final value immediately, causing the window size to be incorrectly restored when the virtual keyboard closes. This happens when the VK opens and closes quicly. make setVirtualKeyboardGeometry a virtual. in the implementation on setVirtualKeyboardGeometry use requestedFrameGeometry() instead of frameGeometry()