Bug 20016: use Modern::Perl in svc scripts

Bug 20016: use Modern::Perl in svc scripts

Test Plan:
- Check that it now says 'use Modern::Perl' and not 'use trict; use
warnings;' in the follwing plugins svc scripts

authentication
bib
bib_profile
checkouts
config/systempreferences
import_bib
new_bib

https://bugs.koha-community.org/show_bug.cgi?id=20016
Signed-off-by: Jon Knight <J.P.Knight@lboro.ac.uk>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>