refactoring for recipient addition page

frontend/pweb/lib/utils/payment/availability.dart

@@ -0,0 +1,26 @@
+import 'package:pshared/models/payment/methods/data.dart';
+import 'package:pshared/models/payment/type.dart';
+
+const List<PaymentType> enabledPaymentTypes = [
+  PaymentType.card,
+  PaymentType.ledger,
+  PaymentType.externalChain,
+];
+
+const List<PaymentType> previewPaymentTypes = [
+  PaymentType.bankAccount,
+];
+
+const List<PaymentType> visiblePaymentTypes = [
+  ...enabledPaymentTypes,
+  ...previewPaymentTypes,
+];
+
+const Set<PaymentType> disabledPaymentTypes = {
+  PaymentType.bankAccount,
+};
+
+MethodMap filterVisiblePaymentTypes(MethodMap source) => {
+      for (final type in visiblePaymentTypes)
+        if (source.containsKey(type)) type: source[type],
+    };