Support for top-level `jsonapi` object

The current state of the OpenApi integration does not add the [jsonapi object](https://jsonapi.org/format/1.1/#document-jsonapi-object) in the OAS file.

In JADNC the JsonApiObject can be included in a response document by configuring `JsonApiOptions.IncludeJsonApiVersion`. Depending on this setting, the JsonApiObject should be included or excluded in the schema of a response document.