Bug 33043: Use process_tt in SIP modules

Bug 33043: Use process_tt in SIP modules

Bug 33030 implements a new helper subroutine to standardize processing of
Template Toolkit syntax outside slips and notices. We should use this
subroutine in the various parts of the SIP server code where we are
currently using Template::process directly.

Test Plan:
1) Apply this patch
2) prove -r t/db_dependent/SIP

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>