add favourites tool

Frontend/lib/mih_objects/loyalty_card.dart

@@ -3,12 +3,16 @@ class MIHLoyaltyCard {
   final String app_id;
   final String shop_name;
   final String card_number;
+  final String favourite;
+  final int priority_index;
 
   const MIHLoyaltyCard({
     required this.idloyalty_cards,
     required this.app_id,
     required this.shop_name,
     required this.card_number,
+    required this.favourite,
+    required this.priority_index,
   });
 
   factory MIHLoyaltyCard.fromJson(Map<String, dynamic> json) {
@@ -18,12 +22,16 @@ class MIHLoyaltyCard {
         "app_id": String app_id,
         "shop_name": String shop_name,
         "card_number": String card_number,
+        "favourite": String favourite,
+        "priority_index": int priority_index,
       } =>
         MIHLoyaltyCard(
           idloyalty_cards: idloyalty_cards,
           app_id: app_id,
           shop_name: shop_name,
           card_number: card_number,
+          favourite: favourite,
+          priority_index: priority_index,
         ),
       _ => throw const FormatException('Failed to load loyalty card objects'),
     };