feat: Add support for labels in automations (#11658)

- Add support for using labels as an action event for automation
 - Fix duplicated conversation_updated event dispatch for labels
 

Fixes https://github.com/chatwoot/chatwoot/issues/8539 and multiple
issues around duplication related to label change events.
---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

spec/models/conversation_spec.rb

@@ -136,7 +136,7 @@ RSpec.describe Conversation do
           notifiable_assignee_change: false,
           changed_attributes: changed_attributes,
           performed_by: nil
-        ).exactly(2).times
+        )
     end
 
     it 'runs after_update callbacks' do