chore: Better error message when join room failed

lib/widgets/future_loading_dialog.dart

@@ -17,9 +17,9 @@ Future<Result<T>> showFutureLoadingDialog<T>({
   required Future<T> Function() future,
   String? title,
   String? backLabel,
-  String Function(dynamic exception)? onError,
   bool barrierDismissible = false,
   bool delay = true,
+  ExceptionContext? exceptionContext,
 }) async {
   final futureExec = future();
   final resultFuture = ResultFuture(futureExec);
@@ -44,7 +44,7 @@ Future<Result<T>> showFutureLoadingDialog<T>({
       future: futureExec,
       title: title,
       backLabel: backLabel,
-      onError: onError,
+      exceptionContext: exceptionContext,
     ),
   );
   return result ??
@@ -58,14 +58,14 @@ class LoadingDialog<T> extends StatefulWidget {
   final String? title;
   final String? backLabel;
   final Future<T> future;
-  final String Function(dynamic exception)? onError;
+  final ExceptionContext? exceptionContext;
 
   const LoadingDialog({
     super.key,
     required this.future,
     this.title,
-    this.onError,
     this.backLabel,
+    this.exceptionContext,
   });
   @override
   LoadingDialogState<T> createState() => LoadingDialogState<T>();
@@ -91,8 +91,7 @@ class LoadingDialogState<T> extends State<LoadingDialog> {
   Widget build(BuildContext context) {
     final exception = this.exception;
     final titleLabel = exception != null
-        ? widget.onError?.call(exception) ??
-            exception.toLocalizedString(context)
+        ? exception.toLocalizedString(context, widget.exceptionContext)
         : widget.title ?? L10n.of(context).loadingPleaseWait;
 
     return AlertDialog.adaptive(