fix: The message field in UnknownRemoteException is typed as String? and the condition will always be false.

lib/main/exceptions/remote/unknown_remote_exception.dart

@@ -1,11 +1,18 @@
 import 'package:tmail_ui_user/main/exceptions/remote/remote_exception.dart';
 
 class UnknownRemoteException extends RemoteException {
+
+  final Object? error;
+
   const UnknownRemoteException({
     super.code,
     super.message,
+    this.error,
   });
 
   @override
   String get exceptionName => 'UnknownRemoteException';
+
+  @override
+  List<Object?> get props => [...super.props, error];
 }

lib/main/exceptions/thrower/remote_exception_thrower.dart

@@ -97,7 +97,7 @@ class RemoteExceptionThrower extends ExceptionThrower {
         } else if (underlyingError is OAuthAuthorizationError) {
           throw underlyingError;
         } else if (underlyingError != null) {
-          throw UnknownRemoteException(message: underlyingError.toString());
+          throw UnknownRemoteException(error: underlyingError);
         } else {
           throw const UnknownRemoteException();
         }