more pleasant progress handling, although somewhat flawed

frontend/lib/structs/trip.dart

@@ -52,6 +52,7 @@ class Trip with ChangeNotifier {
     totalTime = json['total_time'];
     notifyListeners();
   }
+
   void addLandmark(Landmark landmark) {
     landmarks.add(landmark);
     notifyListeners();
@@ -66,12 +67,16 @@ class Trip with ChangeNotifier {
     landmarks.remove(landmark);
     notifyListeners();
   }
-  
+
   void updateError(String error) {
     errorDescription = error;
     notifyListeners();
   }
 
+  void notifyUpdate(){
+    notifyListeners();
+  }
+
   factory Trip.fromPrefs(SharedPreferences prefs, String uuid) {
     String? content = prefs.getString('trip_$uuid');
     Map<String, dynamic> json = jsonDecode(content!);
@@ -80,7 +85,6 @@ class Trip with ChangeNotifier {
     log('Loading trip $uuid with first landmark $firstUUID');
     LinkedList<Landmark> landmarks = readLandmarks(prefs, firstUUID);
     trip.landmarks = landmarks;
-    // notifyListeners();
     return trip;
   }