refactor: replace dictionaries of parameters with bespoke Dataclasses or Pydantic objects

[pbeaucage]

At several points in PyHyper, most notably integration parameters, opaque dictionaries of flexible parameters are used to switch between several different methods, e.g. Nika vs PyFAI geometries.

It would be more robust and usable if these were replaced with a Dataclass that validated complete inputs and provided state management for the integrator.

Other than a discussion item, the main to-do is find other examples where we use dictionaries of parameters to consider conversion.