Fix wayland activation

Adds support for xdg_activation_v1 when calling the application from the
system tray by using KStatusNotifier which supports it.
Listens to XDG_ACTIVATION_TOKEN as it's passed when we are started from
dbus.

qml/main.qml

@@ -158,6 +158,7 @@ Kirigami.ApplicationWindow {
         root.show()
         root.raise()
         root.requestActivate()
+        Controller.raiseWindow(root)
     }
 
     contextDrawer: RoomDrawer {