Bug 17963: TT syntax for notices - Prove that AR_* are compatible

Bug 17963: TT syntax for notices - Prove that AR_* are compatible

Nothing new here since bug 17962, the AR_* notice messages are quite
simple. They send the article_request, patron, biblio, biblioitem, item and
library linked to the article request.

All the fields from these 6 tables should still be accessible using the
TT syntax.

Test plan:
Define TT notice templates for AR_PENDING, AR_PROCESSING, AR_COMPLETED
or AR_CANCELED.

You should manage to create a template to generate the same result as
the historical syntax.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>