fix: Now caches message before update

packages/stream_chat/lib/src/api/channel.dart

@@ -411,6 +411,8 @@ class Channel {
   /// Waits for a [_messageAttachmentsUploadCompleter] to complete
   /// before actually updating the message.
   Future<UpdateMessageResponse> updateMessage(Message message) async {
+    var currentMessage = state?.messages.firstWhere((e) => e.id == message.id);
+
     // Cancelling previous completer in case it's called again in the process
     // Eg. Updating the message while the previous call is in progress.
     _messageAttachmentsUploadCompleter
@@ -459,6 +461,10 @@ class Channel {
     } catch (error) {
       if (error is DioError && error.type != DioErrorType.response) {
         state?.retryQueue?.add([message]);
+      } else if (error is ApiError) {
+        if(currentMessage != null) {
+          state?.addMessage(currentMessage);
+        }
       }
       rethrow;
     }