feat(wip): Update entities and adopt a proper repository workflow for trip "obtention"

frontend/lib/presentation/providers/landmark_providers.dart

@@ -0,0 +1,16 @@
+import 'package:anyway/domain/entities/landmark.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+class IntermediateLandmarksNotifier extends Notifier<List<Landmark>> {
+    @override
+    List<Landmark> build() => [];
+
+    void setLandmarks(List<Landmark> landmarks) {
+        state = List.unmodifiable(landmarks);
+    }
+
+    void clear() => state = [];
+}
+
+final intermediateLandmarksProvider =
+        NotifierProvider<IntermediateLandmarksNotifier, List<Landmark>>(IntermediateLandmarksNotifier.new);