Support other enum naming strategies than camelCase

[hajdamak]

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

Currently EnumNamingStrategies contains only camelCase strategy. Some API guidelines require other strategies like snake_case or UPPER_SNAKE_CASE.

Describe the solution you'd like

EnumNamingStrategies should support other strategies like for example snake_case or UPPER_SNAKE_CASE.

Usage example

No response

Additional context

No response

[cowtowncoder]

Would be provided by #4660 which works but needs some refactoring wrt code reuse.

[cowtowncoder]

Fixed via #4728 will be in 2.19.0.