OCFL backend support

[lnielsen]

[Herrner]

This probably isn't planned for 10.0 anymore, @lnielsen ? Asking for a friend...

[lnielsen]

No, it's only in an assigned state meaning somebody is working on/off on it but no prediction about when.

OCFL is part of the Arcadia 2 project between CERN, Plazi and Data Futures

[lnielsen]

Just linking work that has been done so far:

• https://github.com/inveniosoftware/ocflcore - core python library for writing OCFL structure
• https://github.com/inveniosoftware/invenio-ocfl - generic integration of OCFL for Invenio (provides CLI command for exporting)
• https://github.com/inveniosoftware/invenio-rdm-records/tree/ocfl - integration for RDM-Records to export the records