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

Currently datamodel-code-generator has an option to parse enums as python's string literal (e.g. Literal["A", "B"]), this is great and I'm using it a lot, but the problem is if I want to pass these literal around in my code, I have to define their type once again. e.g:

MyLiterals: TypeAlias = Literal["A", "B"]

def my_func(l: MyLiterals): ...

This is in contrast with all other types and structures generated by datamodel-code-generator. For example if had chosen to use python enums, I would have a MyLiteral enum in the generated code and could have use it in the function's type hint.

Describe the solution you'd like
I like to have an additional option in the CLI to tell datamodel-code-generator to create these literal definitions automatically.

Describe alternatives you've considered

Currently I just copy and paste the literals generated by datamodel-code-generator into a separate file and re-define them, which can be a little non-DRY.