animate popup auto-expire: swipe out instead of instant vanish

modules/NotifService.qml

@@ -105,12 +105,15 @@ QtObject {
         }
     }
 
+    // Signal popups to animate out before removal
+    signal popupExpiring(var notifId)
+
     property Component _expireTimer: Component {
         Timer {
             property var _notifId
             running: true
             onTriggered: {
-                root.dismissPopup(_notifId);
+                root.popupExpiring(_notifId);
                 destroy();
             }
         }