show correct landmark types when fetching from api

frontend/lib/structs/landmark.dart

@@ -3,12 +3,13 @@ import 'dart:convert';
 
 import 'package:shared_preferences/shared_preferences.dart';
 
-
-const LandmarkType museum = LandmarkType(name: 'Museum');
-const LandmarkType monument = LandmarkType(name: 'Monument');
-const LandmarkType park = LandmarkType(name: 'Park');
-const LandmarkType restaurant = LandmarkType(name: 'Restaurant');
-const LandmarkType shop = LandmarkType(name: 'Shop');
+const LandmarkType sightseeing = LandmarkType(name: 'sightseeing');
+const LandmarkType nature = LandmarkType(name: 'nature');
+const LandmarkType shopping = LandmarkType(name: 'shopping');
+// const LandmarkType museum = LandmarkType(name: 'Museum');
+// const LandmarkType restaurant = LandmarkType(name: 'Restaurant');
+const LandmarkType start = LandmarkType(name: 'start');
+const LandmarkType finish = LandmarkType(name: 'finish');
 
 
 final class Landmark extends LinkedListEntry<Landmark>{
@@ -55,7 +56,7 @@ final class Landmark extends LinkedListEntry<Landmark>{
         'location': List<dynamic> location,
         'type': String type,
       }) {
-      // refine the parsing on a few
+      // refine the parsing on a few fields
       List<double> locationFixed = List<double>.from(location);
       // parse the rest separately, they could be missing
       LandmarkType typeFixed = LandmarkType(name: type);
@@ -106,6 +107,14 @@ class LandmarkType {
     // required this.description,
     // required this.icon,
   });
+  @override
+  bool operator ==(Object other) {
+    if (other is LandmarkType) {
+      return name == other.name;
+    } else {
+      return false;
+    }
+  }
 }