overhaul using a trip struct that notifies its ui dependencies

backend/src/main.py

@@ -37,7 +37,7 @@ def new_trip(preferences: Preferences, start: tuple[float, float], end: tuple[fl
         logger.info("No end coordinates provided. Using start=end.")
 
     start_landmark = Landmark(name='start', type='start', location=(start[0], start[1]), osm_type='start', osm_id=0, attractiveness=0, must_do=True, n_tags = 0)
-    end_landmark = Landmark(name='end', type='finish', location=(end[0], end[1]), osm_type='end', osm_id=0, attractiveness=0, must_do=True, n_tags = 0)
+    end_landmark = Landmark(name='finish', type='finish', location=(end[0], end[1]), osm_type='end', osm_id=0, attractiveness=0, must_do=True, n_tags = 0)
 
     # Generate the landmarks from the start location
     landmarks, landmarks_short = manager.generate_landmarks_list(