Create a hera mypy plugin

[sambhav]

Is your feature request related to a problem? Please describe.

Hera currently doesn't have great mypy integration. There are often type errors and input args/paramters are not validated at all.

Describe the solution you'd like

It would be great is hera shipped with a mypy plugin - https://mypy.readthedocs.io/en/stable/extending_mypy.html#extending-mypy-using-plugins

This would be similar to https://docs.pydantic.dev/2.0/api/mypy/

Describe alternatives you've considered

N/A

Additional context

[DanCardin]

I wonder if https://github.com/argoproj-labs/hera/pull/950 fixes this issue, or did you have something else in mind?