Bug 20472: Add format to sample notices

Bug 20472: Add format to sample notices

NOTE: We are only changing English here. A follow-up will care for
the translated languages. (English is in yml format, the remainder
not yet.)

We need to change the following notices:
AR_SLIP, AR_CANCELED, AR_PROCESSING, AR_PENDING and AR_COMPLETED.
In AR_COMPLETED the last sentence about picking up has been modified
too.

Test plan:
Reinstall Koha. Choose English. Check notice text.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>