intent reference generation + propagation

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

@@ -9,11 +9,18 @@ part 'payment_quote.g.dart';
 @JsonSerializable()
 class PaymentQuoteDTO {
   final String? quoteRef;
+  final String? intentRef;
   final QuoteAmountsDTO? amounts;
   final QuoteFeesDTO? fees;
   final FxQuoteDTO? fxQuote;
 
-  const PaymentQuoteDTO({this.quoteRef, this.amounts, this.fees, this.fxQuote});
+  const PaymentQuoteDTO({
+    this.quoteRef,
+    this.intentRef,
+    this.amounts,
+    this.fees,
+    this.fxQuote,
+  });
 
   factory PaymentQuoteDTO.fromJson(Map<String, dynamic> json) =>
       _$PaymentQuoteDTOFromJson(json);