Bug 27673: Replace YAML with YAML::XS

Bug 27673: Replace YAML with YAML::XS

From tht YAML pod:

"""
This module has been released to CPAN as YAML::Old, and soon YAML.pm will be changed to just be a frontend interface module for all the various Perl YAML implementation modules, including YAML::Old.

If you want robust and fast YAML processing using the normal Dump/Load API, please consider switching to YAML::XS. It is by far the best Perl module for YAML at this time. It requires that you have a C compiler, since it is written in C.
"""

See also
https://gitlab.com/koha-community/qa-test-tools/-/merge_requests/35

Test plan:
Try some place where YAML::XS is not used and confirm that it works
correctly

QA note: This patch removes some uses of YAML that were not useful

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Joonas Kylmälä <joonas.kylmala@helsinki.fi>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>