De-duplicate authors based on ORCID

[elichad]

Continuation from #51.

We have canonical entities for authors with ORCIDs (#71), but some author entities use local identifiers rather than the ORCID - so there might be multiple entities with the same name. We can attempt to de-duplicate based on name and also affiliation.

Needs a little care because names aren't necessarily unique, which becomes a bigger issue as the knowledge graph grows. (Perhaps there can be additional metadata provided by WorkflowHub to help disambiguate?)