Extend RelatedObjectsHelper.getAxiomSubjects() to missing property axiom types

[matentzn]

Resolves #1108

• [ ] docs/ have been added/updated
• [x] tests have been added/updated
• [X] mvn verify says all tests pass
• [X] mvn site says all JavaDocs correct
• [X] CHANGELOG.md has been updated

This PR ensures that Property axioms are taken into account correctly when determining base axioms. This is achieved by adding special treatment to a number of property axioms to RelatedObjectsHelper.getAxiomSubjects(), which is responsible to determine which entity is the "subject" of an axiom, which in turn is used by the methods to determine base-iris. For example TransitiveProperty(?p) was previously not considered about ?p - now it is.

I have tested the approach extensively with RO. The changed tests as part of this PR reflect the new behaviour correctly.