Allow inputs to have configurable base class

[mzealey]

All input_types are currently just using BaseModel which by default allows extra fields to be specified. This causes silent data loss if you name the field incorrectly. It would be nice to have a way to either specify at generation time some extra ConfigDict() options, or to have all inputs coming off a single base model which could then be patched by the caller to prevent extra fields if required.

[luci-bytes]

Hello :)

I'd be interested in implementing this. Can I open a PR with my proposed solution?
If so, should I include tests in that PR, and would you prefer updating existing tests or creating new ones?