Support `withXml` ConfigOption

[Chrimle]

• Annotate generated record with @XmlRootElement and @XmlAccessorType(XmlAccessType.FIELD).
• Annotate each generated field with @XmlElement
  • Preferably with the name set to the name of the field (to be consistent with openapi-generator-maven-plugin)

[Chrimle]

Appears to not be supported without further considerations - especially during deserialization, see Java records: Serialization, marshaling, and bean state validation.

Furthermore, looking at Jakarta EE's JAXB API, this is not supported yet: jakartaee/jaxb-api#183.

However, it wouldn't be much effort to add these annotations. But it may cause confusion if it is technically only partially supported (if at all). A disclaimer can be put in the PR/Release, and on the wiki. But until then, this will be marked as Blocked.