Upgrade Harmony API to Pydantic v2

[olp-cs]

Description

Related to harmonydata/harmony#50

Related PR and discussion: harmonydata/harmony#51

• Removed Rocketry: it's not compatible with Pydantic V2 and will be replaced with another library @zaironjacobs
• BaseSettings has moved to a separate package, pydantic-settings.

Testing

Tested on a local system: Ubuntu 24.04 LTS (step-by-step description)

python -m unittest discover tests/local_tests

Before the changes: 18/18 passed
After the changes: 18/18 passed

[zaironjacobs]

@olp-cs There are some deprecated pydantic functions that sill work, but it would be good to update them also to the recommended functions used in v2.

dict() to model_dump(mode="json").
parse_raw(...) to model_validate_json(...).

[olp-cs]

@zaironjacobs I think I have updated it, but please let me know if there is anything else I might have missed.

[woodthom2]

Thanks @olp-cs !