[Feature Request] JsonEnum global configuration

Hello,
I'm working with a backend that sends a significant number of enums formatted in snake case. Upon reviewing the documentation and examples for the json_serializable package, I didn't find a way to globally configure the package to handle snake case enums.

Proposal:
It would be highly beneficial to introduce a feature that allows users to set up a global configuration in the build.yaml file to handle snake case enums. This would streamline the process for projects that frequently interact with backends using this particular naming convention.

Thank you for considering this enhancement.

Versions:
json_serealizable: 6.7.1
json_annotation: 4.8.1