Make extended publication validation configurable in the plugins settings

[dxL1nus]

options to turn off "hard" pulbication validation for:

• validation of codecheck.yml from external repository (Before publication of article (during copyediting) validate (or allow validation) of CODECHECK metadata #12)
• disallowing pulbication when opted-in CODECHECK wasn't started
• if turned off: silently drop the discussed validation cases

[dxL1nus]

This now works:

• If turned on, there will be an extended validation for the publication
  • the OJS CODECHECK Metadata will be compared to the metadata from the codecheck.yml file in the repository
  • when CODECHECK was opted-in, but it wasn't started yet, the publication will be invalid and fail as well
• If turned of, the validation of the CODECHECK status and the structure of the generated YAML will still be active, but the validation described above will not be active and thus in the potential scenario of invalid CODECHECK metadata this will just fail silently