title: Change email subjects for some specific email notifications in Woocommerce
body: <p>I would like to standardize structure of email subjects <em>(for all Woocommerce emails notifications).</em>
  Im using all available filters <a href="https://docs.woocommerce.com/document/change-email-subject-lines/" rel="nofollow noreferrer">from here</a> </p>
  
  <p>But what about “On hold”, “Cancelled”, “Refunded” and “Failed order” email subjects?<br>
  Is there way to change email subject for those emails?</p>