No need to use YAML::Any when YAML::XS is required

[bschmalhofer]

When looking at #2462 I noticed that there is a strangeness in which module is used by Kernel::System::YAML. Here is the present situation:
YAML::XSis required since OTOBO 10.0.0. Perl 5.24 was released in May 2016, so we can assume that YAML::LibYAML 0.62 is available. Kernel/cpan-lib/YAML.pm provides YAML 1.23which dates from February 2017. Judging from https://metacpan.org/release/TINITA/YAML-1.30/changes , this looks like several bugfixes to YAML are not included in the version used by OTOBO. Kernel::System::YAML uses Kernel/cpan-lib/YAML/Any.pm for selecting a YAML implementation. Effectively YAML::XS is picked always, as this is the preferred implementation. https://metacpan.org/dist/YAML/view/lib/YAML.pod recommends using YAML::XS.
_Kernel/cpan-lib/YAML,pmcan't be removed as it is required bySisimai`.

I propose:

• keep Kernel/cpan-lib/YAML.pm and the dir Kernel/cpan-lib/YAML
• require YAML::XS 0.62 in bin/otobo.CheckModules.pl
• use YAML::XS directly in Kernel::System::YAML
• remove the fallback to YAML because something is wrong anyways when YAML::XS can't load the data
• adapt the singular test where the result changes
• only test YAML::XS in scripts/test/YAML/YAML.t

[bschmalhofer]

Not closing the issue yet, as there are three failures related to FormDraft:

Test Summary Report
-------------------
/opt/otobo/scripts/test/Compile.t                                                                         (Wstat: 0 Tests: 1798 Failed: 0)
  TODO passed:   686, 811
/opt/otobo/scripts/test/Selenium/Agent/FormDraft/AgentTicketEmailOutboundDraft.t                          (Wstat: 256 (exited 1) Tests: 48 Failed: 1)
  Failed test:  48
  Non-zero exit status: 1
/opt/otobo/scripts/test/Selenium/Agent/FormDraft/AgentTicketForwardDraft.t                                (Wstat: 512 (exited 2) Tests: 50 Failed: 2)
  Failed tests:  49-50
  Non-zero exit status: 2
/opt/otobo/scripts/test/Selenium/Agent/FormDraft/AgentTicketPhoneCommonDraft.t                            (Wstat: 256 (exited 1) Tests: 47 Failed: 1)
  Failed test:  47
  Non-zero exit status: 1
/opt/otobo/scripts/test/Selenium/Output/Ticket/OverviewSmall.t                                            (Wstat: 256 (exited 1) Tests: 39 Failed: 1)
  Failed test:  39
  Non-zero exit status: 1
/opt/otobo/scripts/test/Selenium/TestingMethods.t                                                         (Wstat: 0 Tests: 36 Failed: 0)
  TODO passed:   21, 24, 28
Files=961, Tests=80406, 3701 wallclock secs (15.66 usr  2.18 sys + 700.23 cusr 97.21 csys = 815.28 CPU)
Result: FAIL
ran tests for product OTOBO 11.0.x on host 1858c59f4cdd .

[bschmalhofer]

Test suite looks fine now. The three new failures were not related to YAML. Closing this issue.

[bschmalhofer]

It would be nice to have a test case where multiple documents are contained in the input. This is an area where the different YAML implementations show differing behavior.
In scalar context, YAML::Syckand ỲAML::PPreturn the first document. YAML, YAML::Old, YAML::XS, und Cpanel::YAML::XS` return the last document.