chore: consider X-original-sender to create contact in case of group mail (#2841)

For emails forwarded from google groups, Google rewrites the FROM address to the group email and the original email will be available under X-Original-Sender. This PR enables chatwoot to handle this case.

Fixes: #2715

app/presenters/mail_presenter.rb

@@ -82,6 +82,10 @@ class MailPresenter < SimpleDelegator
     @mail.from.map(&:downcase)
   end
 
+  def original_sender
+    @mail['X-Original-Sender'].try(:value) || from.first
+  end
+
   private
 
   # forcing the encoding of the content to UTF-8 so as to be compatible with database and serializers