Updates to the support predicates for RDF(S) assertion.

* [RDF_BUILD,SC] Relocated rdf_assert_individual/3 which belongs to RDF (not RDFS).
* [RDF_BUILD,SC] Relocated rdf_assert_property/2 which belongs to RDF (not RDFS).
* [RDF_SCRIPT,SC] Updated the RDF(S) assertions based on the new RDF(S) support predicates.
* [RDFS_BUILD,NEW] Added support predicates for asserting an RDF property's domain and range.