fix: ui refund and sales page

lib/data/models/response/order_response_model.dart

@@ -113,6 +113,7 @@ class Order {
   final DateTime? createdAt;
   final DateTime? updatedAt;
   final List<OrderItem>? orderItems;
+  final bool? isRefund;
 
   Order({
     this.id,
@@ -131,6 +132,7 @@ class Order {
     this.createdAt,
     this.updatedAt,
     this.orderItems,
+    this.isRefund,
   });
 
   factory Order.fromMap(Map<String, dynamic> json) => Order(
@@ -147,6 +149,7 @@ class Order {
         totalAmount: json["total_amount"],
         notes: json["notes"],
         metadata: json["metadata"] ?? {},
+        isRefund: json["is_refund"],
         createdAt: json["created_at"] == null
             ? null
             : DateTime.parse(json["created_at"]),
@@ -175,6 +178,7 @@ class Order {
         "metadata": metadata,
         "created_at": createdAt?.toIso8601String(),
         "updated_at": updatedAt?.toIso8601String(),
+        "is_refund": isRefund,
         "order_items": orderItems == null
             ? []
             : List<dynamic>.from(orderItems!.map((x) => x.toMap())),