Handles messages update events

lib/lists/conversation_messages_list.dart

@@ -48,4 +48,10 @@ class ConversationMessagesList extends ListBase<ConversationMessage> {
       if (message.id < firstMessageID) firstMessageID = message.id;
     return firstMessageID;
   }
+
+  /// Replace a message by another one (if any)
+  void replace(ConversationMessage msg) {
+    final index = this.indexWhere((t) => t.id == msg.id);
+    if (index >= 0) this[index] = msg;
+  }
 }