add a filter for has-author

[tautme]

I would like to narrow a search down by has-author, in the same way has-affiliation is used.

[gbilder]

Agreed. We should have has-contributor at very least.

But also note that there is a has-orcid. Not the same, but might help until we have a has-contributor or better.

[croucour]

Any update ?

[ppolischuk]

Apologies for the delay. We're still focused on getting the Crossref REST API migrated from Solr to Elasticsearch. We hope to wrap that up in the next few months and move on to feature requests like this soon. Thanks for checking back in, and stay tuned.