Support marker for transitive properties (for inference and display purposes)

[HolgerKnublauch]

It would be good to introduce a boolean property sh:transitive that can be applied to sh:PropertyShapes.

For example, skos:broader and rdfs:subClassOf could be marked transitive.

Inference engines could use this generically to determine whether the intermediate (indirect) triples should be inferred.

Display engines can use this info to decide whether values should be rendered in a tree hierarchy.

I am sure there are more use cases.

There is owl:TransitiveProperty but that's a global flag, and it would require using a different namespace and with different semantics than sh:transitive.

As this is shared across multiple use cases, it may make sense to add this to Core similar to properties like sh:order and sh:group.

[afs]

With other work like #185, #147, there needs to be a single approach to transitive properties.

It is proposed that rules will have TRANSITIVE(propertyURI) (and in RDF syntax), SYMMETRIC and INVERSE (section 4.2.1) to make writing these features simpler, and also to allow easy of implementation by specialised code and in engines that otherwise do not support full rules recursion.

For UI, there needs to be a general way to add annotations. Adding one a time seems unlike to end up with a coherent approach.
Example: sh:order is defined in core but is also in AF.