[REQ] openapi-generator-maven-plugin oneOf support

[tillias]

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

We have following JSON Schema

{
  "$id": "https://example.com/some.schema.json",
  "title": "some",
  "type": "object",
  "properties": {
    "id": {
      "type": "string"
    },
    "someEnum": {
      "type": "object",
      "oneOf": [
        {
          "properties": {
            "businessId": {
              "const": "001"
            },
            "name": {
              "const": "first"
            }
            ...
          },
          "required": ["businessId", "name"]
        },
        {
          "properties": {
            "businessId": {
              "const": "002"
            },
            "name": {
              "const": "second"
            }
          },
          "required": ["businessId", "name"]
        }
      ]
    }
  },

  "required": ["id", "someEnum"]
}

Describe the solution you'd like

It would be nice supporting generation of "someEnum". At the moment it is simply empty class

Describe alternatives you've considered

joelittlejohn/jsonschema2pojo#1193