Use pydantic instead of jsonschema for legacy store

[bepri]

What needs to get done

The legacy code for parsing the store responses should use Pydantic models instead of validating with the jsonschema library.

Why it needs to get done

The current legacy code uses a pinned version of jsonschema that is very difficult to upgrade. Instead of upgrading, the code should just move over to using the more modern pydantic models.