[Feature] Python should be able to automatically cast strings to enums and throw runtime error where this is not possible

[billytrend-cohere]

Problem description

Python should be able to automatically cast strings to enums and throw runtime error where this is not possible

Why would it be useful?

Useful in our case for backwards compatibility but also makes it convenient when you are passing strings around.

Describe the solution (optional)

enum arguments should be string union enum

[dsinghvi]

This is supported in the latest version of Python generator with the following config:

config: 
  pydantic_config: 
    use_str_enum: true