Enhancement: Validate config with pydantic

[benatouba]

Would you be interested in implementing Pydantic classes for config model validation? This would yield type safety and greatly help with testing/lower the need for tests of config?

Pydantic GitHub is well-established, widely used and very perfomant (maybe not the most important point here). But I don't think it will go away anytime soon and greatly helps with further code development.