[blms]

In this PR

• Add a one-off management command, a script to move 74 toponyms in Chig1, Chig2 and Borg back to their original folios; they'd ended up on the wrong folios when their folio records were renamed
  • only reports unless run with --apply, and it skips any record whose number or toponym count has changed.
• Require confirmation to rename a folio that has toponyms
  • Only allow such renames on the Folio's own admin page, not in the Manuscript admin's "folios" table
• Allow adding folios from the Manuscript admin and the Folios admin, and reject duplicate folio numbers within a manuscript