Align schema validation rules in pydantic models with JSON Schema

[fmigneault]

@rbavery cloned issue crim-ca/mlm-extension#36 on 2024-09-13:

🚀 Feature Request

I'm finding that the JSON Schema has more specific (and sensible) rules for a number of fields. So far I'm seeing

framework_version: must follow numerical structure with alphanumerics allowed at the end

dim_order: duplicates not allowed

I can make the updates in the pydantic models.

🔉 Motivation

When a user of stac_model tries to construct the MLM metadata as JSON, they might not follow all the rules in the JSON Schema but the pydantic models won't raise errors. This will cause a problem when the user tries to validate the pystac item against the schema.

📡 Alternatives

Keep as is.