fix: Consider the emails where in-reply-to header has multiple values (#7715)

- Return the first message id for now to avoid the errors and subsequently missing the message.
- Use .last instead of .first to avoid expensive query.
- Fix array response in response bot.

Fixes:  https://linear.app/chatwoot/issue/CW-2358/activerecordstatementinvalid-pgdatatypemismatch-error-argument-of-and

enterprise/app/services/enterprise/message_templates/response_bot_service.rb

@@ -61,7 +61,7 @@ class Enterprise::MessageTemplates::ResponseBotService
   end
 
   def create_messages(response, conversation)
-    response = process_response_content(response)
+    response = process_response_content(response).first
     create_outgoing_message(response, conversation)
   end