feat: Implement switching between accounts (multi user support), still WIP

lib/features/login/model/client_certificate_form_model.dart

@@ -0,0 +1,19 @@
+import 'dart:convert';
+import 'dart:typed_data';
+
+class ClientCertificateFormModel {
+  static const bytesKey = 'bytes';
+  static const passphraseKey = 'passphrase';
+
+  final Uint8List bytes;
+  final String? passphrase;
+
+  ClientCertificateFormModel({required this.bytes, this.passphrase});
+
+  ClientCertificateFormModel copyWith({Uint8List? bytes, String? passphrase}) {
+    return ClientCertificateFormModel(
+      bytes: bytes ?? this.bytes,
+      passphrase: passphrase ?? this.passphrase,
+    );
+  }
+}