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?

BUG: 458415