small fixes for single payout and big chunck for multiple payouts

frontend/pshared/lib/data/dto/payment/quotes.dart

@@ -5,19 +5,21 @@ import 'package:pshared/data/dto/payment/payment_quote.dart';
 
 part 'quotes.g.dart';
 
-
 @JsonSerializable()
 class PaymentQuotesDTO {
   final String quoteRef;
+  final String? idempotencyKey;
   final PaymentQuoteAggregateDTO? aggregate;
   final List<PaymentQuoteDTO>? quotes;
 
   const PaymentQuotesDTO({
     required this.quoteRef,
+    this.idempotencyKey,
     this.aggregate,
     this.quotes,
   });
 
-  factory PaymentQuotesDTO.fromJson(Map<String, dynamic> json) => _$PaymentQuotesDTOFromJson(json);
+  factory PaymentQuotesDTO.fromJson(Map<String, dynamic> json) =>
+      _$PaymentQuotesDTOFromJson(json);
   Map<String, dynamic> toJson() => _$PaymentQuotesDTOToJson(this);
 }