Bug 24594: Rewrite authorities_normal_marc21 to YAML

Bug 24594: Rewrite authorities_normal_marc21 to YAML

YAML version of marc21 mandatory authorities_normal_marc21.

To test:
1) Do a clean install with mandatory data,
   dump table auth_types, auth_tag_structure and
   auth_subfield_structure, reserve.

2) Apply this patch and it's dependencies

3) Do a clean install, dump again and compare
   No major differences expected

4) Try translation
  a) Go to misc/translator
  b) create files for a new language
     ./translate create xx-YY
  c) Check new file po/xx-YY-instaler-MARC21.po
     Verify strings from this file.
  d) Install new language
     ./translate install xx-YY
  e) Try clean install with new files

NOTE: This patch fails with qa tools!
Reason is that qa tools use YAML.pm module to
check files, but Installer.pm or LangInstaller.pm
are using YAML::Syck, using that module gives
no error, check for example:

perl -e 'use YAML::Syck qw( LoadFile ); $y = LoadFile("authorities_normal_marc21.yml");'
No error!

perl -e 'use YAML qw( LoadFile ); $y = LoadFile("authorities_normal_marc21.yml");'
Error!

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>