Connect customer quotations and payment execution to Sendico (#50)

frontend/packages/sxchnge_wallet/lib/src/models/wallet.dart

@@ -25,9 +25,14 @@ class CurrencyAccount {
     required this.currency,
     required this.precision,
     required this.available,
+    this.payoutMethod = '',
+    this.payoutLabel = '',
+    this.canFund = true,
   });
   final String id, currency;
   final int precision, available;
+  final String payoutMethod, payoutLabel;
+  final bool canFund;
 
   /// Locale-aware decimal input, integer money. Grouping/exponents are rejected.
   int? parse(String input) {