Change `EnumNamingStrategy.convertEnumToExternalName()` to take `MapperConfig` argument

[cowtowncoder]

Describe your Issue

For some reason there is an oversight in EnumNamingStrategy such that configuration is not passed to it. We should fix that for 3.0 (cannot change due to compatibility requirements in 2.x).

[yihtserns]

I wonder if it wasn't a EnumNamingStrategy.convertEnumToExternalName method parameter because any custom implementation can get it here if they need it:

class SomeCustomAnnotationIntrospector extends NopAnnotationIntrospector {
   ...

   @Override
   public Object findEnumNamingStrategy(MapperConfig<?> config, ...) {
      return new CustomEnumNamingStrategy(config);
   }
}

🤔