fix: Migrate notes when merging the contacts (#8749)

Fixes: https://linear.app/chatwoot/issue/CW-2987/migrate-notes-of-the-secondary-contact-to-primary-contact-when-merging

app/actions/contact_merge_action.rb

@@ -12,6 +12,7 @@ class ContactMergeAction
       merge_conversations
       merge_messages
       merge_contact_inboxes
+      merge_contact_notes
       merge_and_remove_mergee_contact
     end
     @base_contact
@@ -33,6 +34,10 @@ class ContactMergeAction
     Conversation.where(contact_id: @mergee_contact.id).update(contact_id: @base_contact.id)
   end
 
+  def merge_contact_notes
+    Note.where(contact_id: @mergee_contact.id, account_id: @mergee_contact.account_id).update(contact_id: @base_contact.id)
+  end
+
   def merge_messages
     Message.where(sender: @mergee_contact).update(sender: @base_contact)
   end