Bug 30797: Add the calendar.inc include to addbiblio.tt

Bug 30797: Add the calendar.inc include to addbiblio.tt

addbiblio.tt throws the '$(...).flatpickr is not a function' because it
is missing includes to flatpickr.min.js and shortcut-buttons-flatpickr.min.js

To fix this the addbiblio.tt should include the calendar.inc file (like
additem.tt does) which includes to those aforementioned JS files.

Test plan:
1. Edit a MARC bibliographic framework
2. Make the 902$d subfield visible in the Editor
3. Also set the 902$d subfield plugin='dateaccessioned.pl'
4. Catalogue a new biblio record
5. Notice the 902$d subfield has not been pre-populated with todays date
6. Right click, choose 'Inspect', observe this JS error in the console: "Uncaught
TypeError: $(...).flatpickr is not a function"
7. Apply patch, and restart services
8. Repeat steps 4-6 and this time observe the 902$d is pre-populated,
and there is no flatpickr JS error in the console

Sponsored-by: Chartered Accountants Australia and New Zealand
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>