[Kickoff] Open leave menu on press

It's what toolbuttons that spawn a menu usually do.

Also lets you do the "press, move to menu item, release" dance.


(cherry picked from commit 18f37f92)

applets/kickoff/package/contents/ui/LeaveButtons.qml

@@ -100,7 +100,7 @@ Item {
 
         // Make it look pressed while the menu is open
         checked: contextMenu.status === PlasmaComponents.DialogStatus.Open
-        onClicked: contextMenu.openRelative()
+        onPressed: contextMenu.openRelative()
 
         Keys.forwardTo: [leaveButtonRoot]