redesigned payment page + a lot of fixes

frontend/pweb/lib/models/recipient/method_snapshot.dart

@@ -0,0 +1,62 @@
+import 'package:collection/collection.dart';
+
+import 'package:pshared/data/mapper/payment/method.dart';
+import 'package:pshared/models/payment/methods/data.dart';
+import 'package:pshared/models/payment/type.dart';
+import 'package:pshared/models/recipient/payment_method_draft.dart';
+
+
+class RecipientMethodSnapshot {
+  final PaymentType type;
+  final String? existingId;
+  final Map<String, dynamic>? data;
+  final Map<String, String>? metadata;
+
+  static final DeepCollectionEquality _mapEquality =
+      const DeepCollectionEquality();
+
+  const RecipientMethodSnapshot({
+    required this.type,
+    required this.existingId,
+    required this.data,
+    required this.metadata,
+  });
+
+  factory RecipientMethodSnapshot.fromDraft(RecipientMethodDraft draft) {
+    return RecipientMethodSnapshot(
+      type: draft.type,
+      existingId: draft.existing?.id,
+      data: _dataToSnapshot(draft.data),
+      metadata: _metadataToSnapshot(draft.data),
+    );
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    return other is RecipientMethodSnapshot &&
+        other.type == type &&
+        other.existingId == existingId &&
+        _mapEquality.equals(other.data, data) &&
+        _mapEquality.equals(other.metadata, metadata);
+  }
+
+  @override
+  int get hashCode => Object.hash(
+        type,
+        existingId,
+        _mapEquality.hash(data),
+        _mapEquality.hash(metadata),
+      );
+}
+
+Map<String, dynamic>? _dataToSnapshot(PaymentMethodData? data) {
+  if (data == null) return null;
+  return data.toJsonMap();
+}
+
+Map<String, String>? _metadataToSnapshot(PaymentMethodData? data) {
+  final metadata = data?.metadata;
+  if (metadata == null) return null;
+  return Map<String, String>.from(metadata);
+}