SHACL support

[dgarijo]

There are cases where the OpenAPI validation is not enough for validating the restrictions of the ontology.
For example, if a range has a complex expression with intersections and unions. In these cases, we could allow for the possibility of using SHACL shapes for validation. Shapes are generated from ontologies by programs like astrea: https://astrea.linkeddata.es/

Ontology engineers may also want to have their shapes created instead of editing the openapi schema. The only drawback that I see of this is the overhead that the extra validation would imply.