Add handler for KUnifiedPush messageReceived events

src/notificationsmanager.h

@@ -83,6 +83,11 @@ public:
      */
     void clearInvitationNotification(const QString &roomId);
 
+    /**
+     * @brief Display a native notification for the given push notification.
+     */
+    void postPushNotification(const QByteArray &message);
+
     /**
      * @brief Handle the notifications for the given connection.
      */