Cancel URL webform compatibility
Cancel URL with Drupal 7 Webform was not working correctly until this was applied. As discussed but in the same thread this solution won't be applied for Drupal 8.
Webform already calls the payment processor to set success/cancel URL https://github.com/colemanw/webform_civicrm/blob/8.x-5.x/src/WebformCivicrmPostProcess.php#L2113 but it is not set correctly by civi OR payment processor code (in case of Redsys).
It should be ensured that the cancel URL at the level of this extension is set correctly.