UserActionsMenu: Add "Move &To Current Desktop" action from task manager for X11
Task Manager has this option, so let's keep them consistent. Surprisingly, when a window is set to "All Desktops", choosing "All Desktops" again clears that flag, i.e. sets the window back to only single desktop. But it is not intuitive at all. So let's have this separate action to pin a window to current desktop.
Note: Wayland allows for multiple but not all desktops to be assigned to a window, so it works differently there. Should we have a similar option there too?
Edited by ivan tkachenko