Baroque Art exporter: a monument’s contact details (#2462)

Baroque Art exporter: a monument's contact details (#2462)

Legacy's Baroque Art monument sheet opens the monument's visitor contact
from "Contact Details" (database_item.php): its address, phone, fax,
e-mail and responsible institution. The importer keeps them on each
language's row (extra.monument_contact); the exporter now ships them as
the translation's `contact`. Islamic Art and Sharing History have that
block commented out, so their exporters are unchanged.

Part of #2404

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>