Add support for static type checking

[espetro]

Currently, it is only possible to get insights from the refinement types at runtime, via the @refined decorator. Ideally, it should also be possible to get insights with static type checking tools such as mypy or pyright.

One way to do it is by creating "plugins". Moreover, should we rework the type-checking methods in the library so it could work with multiple "targets" (i.e. runtime checks with @refined, and build-time checks with e.g. mypy)?