Use Hydra vocab for paging info

[nicholascar]

See https://www.hydra-cg.com/spec/latest/core/ & http://www.hydra-cg.com/.

Must decide on Linked Data Platform norms v. current setup v. Hydra for paging etc.

[pietercolpaert]

Another spec to consider: the collection design of TREE is designed to be compatible with both Hydra and LDP, and supports adding more semantics to what your pagination links mean (e.g., describe an ordering, or add more than just next, first, last, previous): https://w3id.org/tree/specification

[nicholascar]

Thanks @pietercolpaert! The paging semantics here have, so far been pretty bad so I think this is a good suggestion to move to the robust hydra. The HTTP paving Link headers are standard, so we can keep those.

I’ll try to fold in hydra soon: we are working on a major update to this API now which adds support for Python’s new FastAPI, not just Flask, so we can probably do all this in the same move.