Add options to override how Django Choice fields are converted to Enums

[jkimbo]

This PR resolves #185 and #843 by adding 2 new settings to customise the naming of the Enum types generated from Django Choice fields.

• DJANGO_CHOICE_FIELD_ENUM_V3_NAMING changes all enum type names to a naming convention that should prevent duplicates. This format will be the default in v3.
• DJANGO_CHOICE_FIELD_ENUM_CUSTOM_NAME allows you to define a custom function to determine what the enum type name should be

[MisterGlass]

Looks great!

[zbyte64]

While introducing new settings is to be avoided, both have their rationale.

DJANGO_CHOICE_FIELD_ENUM_V3_NAMING is a path forward to conflict free defaults.

DJANGO_CHOICE_FIELD_ENUM_CUSTOM_NAME does take away control from the applications for extreme remedies. However it appears to encourage importing models into the settings, this should be avoided. Instead we should support a string to be imported using https://docs.djangoproject.com/en/3.0/_modules/django/utils/module_loading/

[jkimbo]

@zbyte64 good point about using module loading rather than direct references. I'll update the PR.

Also I don't understand the rest of your comment? Are you suggesting changes to the documentation or just re-iterating what the purpose of the change is?

[zbyte64]

Was just re-iterating / thinking out loud. Updating the settings to allow a string specified import was my only recommend action.

[jkimbo]

@zbyte64 PR is ready for another review

[zbyte64]

Thank you for tackling this

[bennett-jacob]

When is this going to be merged?

[rarenatoe]

Someone merge and deploy this please

[jkimbo]

Sorry for the delay with this (I've been on holiday). Shipping this now