Add missing custom IRIs for NoAssertionElement and NoneElement (for owl:sameAs)

[bact]

Find this during diagram update for SpdxOrganization,
do the custom IRI of NoAssertionElement and NoneElement missing in the spec's model description?

Currently these are IRIs of NoAssertionElement, NoneElement, NoAssertionLicense and NoneLicense in the digrams:

These are "custom" or "simplified" IRIs for those individuals.

However, there are differences between the spec and the diagram:

• NoAssertionElement

  • Current IRI in spec: https://spdx.org/rdf/3.0.1/terms/Core/NoAssertionElement
  • Current IRI in diagram: https://spdx.org/rdf/3.0.1/terms/Core/NoAssertion

• NoneElement

  • Current IRI in spec: https://spdx.org/rdf/3.0.1/terms/Core/NoneElement
  • Current IRI in diagram:https://spdx.org/rdf/3.0.1/terms/Core/None

• NoAssertionLicense

  • Current IRI in spec: https://spdx.org/rdf/3.0.1/terms/Licensing/NoAssertion
  • Current IRI in diagram: https://spdx.org/rdf/3.0.1/terms/Licensing/NoAssertion

• NoneLicense

  • Current IRI in spec: https://spdx.org/rdf/3.0.1/terms/Licensing/None
  • Current IRI in diagram: https://spdx.org/rdf/3.0.1/terms/Licensing/None

• IRIs in spec and digram for License individuals are matched.

  • But IRIs of Element individuals are not matched.

• From the diagram and the Licensing spec, it is likely that custom IRIs in NoneElement and NoAssertionElement are missing.

  • This PR adds those two IRIs: Core/None and Core/NoAssertion

• Note that: adding these IRIs will not break the model, neither v3.0.1 nor v3.0.0.

  • Core/NoneElement and Core/NoAssertionElement are still valid and accessible

[zvr]

No, there is no need for custom IRIs for these individuals.

Every class, property, individual gets an automatic IRI. These are perfectly fine for almost all cases.
In this case it's https://spdx.org/rdf/3.0.1/terms/Core/NoneElement and it's fine.

We've added custom IRIs to individual license elements to have a something simpler than mentioning ExpandedLicensing. These two are the exception, not the rule.
So, besides the automatically generated https://spdx.org/rdf/3.0.1/terms/ExpandedLicensing/NoneLicense there is also https://spdx.org/rdf/3.0.1/terms/Licensing/None and they are defined to be the same.

[bact]

Thanks.

Then, do we need to update the diagram?