Update triplestore loader to add ontology version IRI to all nodes.

[dosumis]

Use case: it can be useful to display version info in downstream tools.

Proposal for how this should look:

ontology_version_iri: {full version iri} e.g. http://purl.obolibrary.org/obo/cl/releases/2021-06-29/cl.owl
ontology_version: {just the version string part of the version IRI - following OBO standards} e.g. 2021-06-29

Possible issues with this:

• If loading a merged release, do imported terms get the IRI of the ontology they are imported into?
  • Yes.

@hkir-dev - not sure which repo to put this on. Please move as appropriate.

[hkir-dev]

related topic: obophenotype/brain_data_standards_ontologies#145