[BUG] XML attribute incompatible with JSON $ref

Description

When using reference to describe property, the xml meta information is lost in the parsing.
It is therefore impossible when using reference to define xml related information. This seems like a big limitation.

openapi-generator version

3.0.2

OpenAPI declaration file content or url

openapi: 3.0.2
paths: {}
components:
  schemas:
    XXX:
      type: object
      properties:
        MyAttribute:
          $ref: "#/components/schemas/MyAttributeType"
          xml:
            attribute: true
            name: MyAttributeSpecialName

Suggest a fix

No idea as when using $ref it is supposed to replace the block content, therefore I don't know how this should be handled.

Start with the supplied OpenAPI declaration and reproduce how the parser handles a property combining $ref with xml metadata. Trace the relevant parsing and generation path; done means the xml attribute and name remain available when the referenced schema is used, with regression coverage for this example.