Fix Birjandi authority

[ahankinson]

This PR fixes the authority records for "Birjandī, ʻAbd al-ʻAlī ibn Muḥammad ibn Ḥusayn" to normalize references to this person and consolidate them under the same VIAF record.

This arose out of a conversation at the Islamic Scientific Manuscripts Initiative.

[andrew-morrison]

FYI, ideally, where a key="person_f123" has been replaced with key="person_4567890", because they're in VIAF, the persons_base.xml authority file should be edited too, to move the person_f123 entry to persons_deleted.xml. But it isn't essential, as the indexer will skip over (and inform the person who runs it) any authority file entries that no longer have an instances in the TEI records.