fix: Add an action cable events for label updates (#5694)

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

app/models/conversation.rb

@@ -262,6 +262,8 @@ class Conversation < ApplicationRecord
     previous_labels, current_labels = previous_changes[:label_list]
     return unless (previous_labels.is_a? Array) && (current_labels.is_a? Array)
 
+    dispatcher_dispatch(CONVERSATION_UPDATED, previous_changes)
+
     create_label_added(user_name, current_labels - previous_labels)
     create_label_removed(user_name, previous_labels - current_labels)
   end