Automate/sync pyopds2 pydantic models (based on readium web manifest publication schema)

[mekarpeles]

https://drafts.opds.io/opds-2.0.html#appendix-a-json-schema

pyopds2 should implement a pydantic model for each of the following:
https://github.com/opds-community/drafts/tree/main/schema
https://github.com/readium/webpub-manifest/tree/master/schema

@HadrienGardeur can you help us understand the difference between these two links?

As part of this issue, we can write a script that programatically runs code gen (https://docs.pydantic.dev/latest/integrations/datamodel_code_generator) versus the opds schema files.

[HadrienGardeur]

The OPDS JSON Schema is meant for an OPDS feed or publication but since the OPDS 2.0 model is based on RWPM, a lot of the JSON Schema is shared across the two of them.

Extensions that are specific to OPDS are listed separately (https://github.com/opds-community/drafts/blob/main/schema/properties.schema.json) but referenced from the RWPM schema as well: https://github.com/readium/webpub-manifest/blob/master/schema/link.schema.json#L50

Since you're providing an OPDS 2.0 library, you should target the core structures for OPDS:

• Feed: https://github.com/opds-community/drafts/blob/main/schema/feed.schema.json
• Publication: https://github.com/opds-community/drafts/blob/main/schema/publication.schema.json
• Authentication Document: https://github.com/opds-community/drafts/blob/main/schema/authentication.schema.json