Missing rdf:type owl:Ontology causes non-intelligible fail

[matentzn]

ROBOT convert and generally the OWL API is robust to the absence of an ontology declaration like <http://purl.obolibrary.org/obo/my-ont.owl> rdf:type owl:Ontology .

Can we make this statement optional for obographs parser as well? It just took me 1 hour to debug this, and I think others may struggle hard with this as well if they hit the issue.

[matentzn]

@caufieldjh are you ok with adding the annotate subcommand as a preprocessing step for now or do we need to prioritise fixing this?

[caufieldjh]

Sure, I have a hacky fix to account for this downstream so I'll add an annotate to ensure a full declaration gets added.
Would probably make life easier in general re: obographs if the declaration wasn't mandatory, particularly when they don't get added by robot extract.