feat: add references header to reply emails (#11719)

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

app/presenters/mail_presenter.rb

@@ -100,6 +100,7 @@ class MailPresenter < SimpleDelegator
       message_id: message_id,
       multipart: multipart?,
       number_of_attachments: number_of_attachments,
+      references: references,
       subject: subject,
       text_content: text_content,
       to: to
@@ -115,6 +116,12 @@ class MailPresenter < SimpleDelegator
     @mail.in_reply_to.is_a?(Array) ? @mail.in_reply_to.first : @mail.in_reply_to
   end
 
+  def references
+    return [] if @mail.references.blank?
+
+    Array.wrap(@mail.references)
+  end
+
   def from
     # changing to downcase to avoid case mismatch while finding contact
     (@mail.reply_to.presence || @mail.from).map(&:downcase)