Added Localizations and ran small fixes

frontend/pweb/lib/services/auth.dart

@@ -0,0 +1,18 @@
+class AuthenticationService {
+  Future<bool> verifyTwoFactorCode(String code) async {
+    await Future.delayed(const Duration(seconds: 2));
+
+    if (code == '000000') {
+      return true;
+    } else {
+      throw const WrongCodeException();
+    }
+  }
+}
+
+class WrongCodeException implements Exception {
+  const WrongCodeException();
+
+  @override
+  String toString() => 'WrongCodeException';
+}