7.0.x - Fix Enum JSON/XML Serialization for Round-Trip Compatibility

[codeconsole]

The Problem

Grails had asymmetric enum handling that broke round-trips:

POST/PUT (What you send):

{"stage":"SUBMIT"}

GET (What you received back):

{"stage":{"enumType":"com.example.ChallengeStage","name":"SUBMIT"}}

Result: You couldn't POST back what you GET!

The Fix

Enums now serialize the same way they deserialize - as simple strings:

POST/PUT (What you send):

{"stage":"SUBMIT"}

GET (What you get back):

{"stage":"SUBMIT"}

Result: What you POST is what you GET.

Opt-in via application.yml:

 grails: converters: json: enum: format: simple xml: enum: format: simple

[jdaugherty]

@codeconsole can you please update the documentation too?

[codeconsole]

@codeconsole can you please update the documentation too?

done