Add harvesting script for OpenAlex

[hauschke]

Is your feature request related to a problem? Please describe.
OpenAlex is the rising star in open research information and provides rich metadata for more than 200 million publications. It would be very useful to have a working harvester script for this data source.

Describe the solution you'd like
A reusable script, maybe based on the JSON fetch.

Describe alternatives you've considered
None, at least not for the VIVO harvester.

Additional context
API overview: https://docs.openalex.org/how-to-use-the-api/api-overview

[hauschke]

Potential example queries:

https://api.openalex.org/works?filter=authorships.institutions.ror:https://ror.org/04aj4c181 # harvesting publications from TIB – Leibniz Information Centre for Science and Technology. exchange the ROR ID to test with your institution.

https://api.openalex.org/works?page=1&filter=primary_topic.id:t10215,publication_year:2022-2024 # harvesting of publications from the subfield "Semantic Web and Ontology Develoment", should result in ca. 9-10k publications (bearbeitet)

https://api.openalex.org/works?page=1&filter=primary_location.source.id:s4210195326 # harvesting of publications from the journal "Quantitative Science Studies".