Use MARCAuthorityControlField008 in AddAuthority for empty 008s

Use MARCAuthorityControlField008 in AddAuthority for empty 008s

The old default value for field 008 didn't have the correct length,
which could potentially cause data corruptions.

Uses the MARCAuthorityControlField008 preference added by BUG4839.

http://bugs.koha-community.org/show_bug.cgi?id=7072
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
(cherry picked from commit 6408547cc0d396c8b9d29e1f7617637d9c12a9a6)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>