Bug 27398: Made values in number patterns subscription length translatable

Bug 27398: Made values in number patterns subscription length translatable

TEST PLAN:
Check that the subscription length options when editing or adding a
numbering pattern in the serials module are translatable. check that
the hard coded values are gone.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit a9df4daab1f780f14fed1fba9f4afad8c4c73d30)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>