Shift to a widely-used data model for collection and aggregation

[anjackson]

The current data model used for indexing the iPRES publications is rather ad-hoc, very roughly based on Dublin Core, but a bit messy because I want:

• presentation, stream and papers on the same record (not that that's implemented yet).
• a fairly flat model so it can be easily mapped to CSV.

There are other options to consider:

• https://python.commonmeta.org/ https://github.com/front-matter/commonmeta-py
• https://www.crossref.org/documentation/schema-library/markup-guide-record-types/conference-proceedings/
• https://github.com/citation-file-format/citation-file-format?tab=readme-ov-file#citation-file-format (intended for software/datasets)
• https://rioxx.net/profiles/v3-0-final/ with https://vocabularies.coar-repositories.org/resource_types/
• plain old https://pythonhosted.org/dcxml/usage.html