remove geo:asWKT from cco:GeospatialOntology

[jonathanvajda]

Resolves an issue #946 where an IRI, that is being maintained outside of CCO's namespace, is asserted with annotations and claims that it is curated in CCO GeospatialOntology.

[dr-shorthair]

Perhaps this will help.

GeoSPARQL is currently in revision, on the schedule documented here: https://opengeospatial.github.io/ogc-geosparql/

Most significantly, the (official, though non-normative) GeoSPARQL-BFO mapping has been completely overhauled.
The mapping can be inspected

• in a tabulation in the Editor's Draft here: https://opengeospatial.github.io/ogc-geosparql/geosparql-next/spec.html#basic_formal_ontology_bfo_and_common_core_ontologies_cco
• or in an RDF (TTL) file here: https://github.com/opengeospatial/ogc-geosparql/blob/master/geosparql-next/rdf/alignments/source/bfo.ttl

This mapping provides a bridge between BFO/CCO and GeoSPARQL.
Note that geo:asWKT is a subproperty of geo:hasSerialization, which will usually appear as a property of an individual geo:Geometry, which is understood as a descriptive information content entity.

The mapping was influenced by the conversation here: #827

@nicholascar and @situx assisted.