#371 Post-Python 3: Publisher update is filed for a delete publisher

[Ahasuerus]

When a Publisher Update submission is displayed on the submission review page and the reviewing moderator clicks "Approve" after the displayed publisher record was deleted via another submission, the filing process applies the filing logic to a no longer existing publisher record. This can insert values for a non-existent publisher into trans_publisher_name. The filing process should reject the submission instead.