Project query parameters parents_as_list and subtree_as_list do not work

[Colleen Murphy]

The api-ref documents the parents_as_list and subtree_as_list parameters to the GET /v3/projects/{project_id} endpoint to show either a project's heritage or a project's descendants as a full list of project objects, as opposed to a plain list of IDs which can be requested with the parents_as_ids and subtree_as_ids parameters:

https://docs.openstack.org/api-ref/identity/v3/?expanded=show-project-details-detail#show-project-details

When using these options, the returned result is empty:

$ curl -s -H "x-auth-token: $token" "http://localhost/identity/v3/projects/e905aaf2bc7249e2916f3789f255ef8a?parents_as_list" | jq .
{
  "project": {
    "id": "e905aaf2bc7249e2916f3789f255ef8a",
    "name": "foo",
    "domain_id": "511b180417954e29bb03212a177f58bd",
    "description": "",
    "enabled": true,
    "parent_id": "c8364aeb843c485cab13a3ff77e3f4e5",
    "is_domain": false,
    "tags": [],
    "options": {},
    "parents": [],
    "links": {
      "self": "http://192.168.122.96/identity/v3/projects/e905aaf2bc7249e2916f3789f255ef8a"
    }
  }
}

while using *_as_ids correctly returns project IDs:

$ curl -s -H "x-auth-token: $token" "http://localhost/identity/v3/projects/e905aaf2bc7249e2916f3789f255ef8a?parents_as_ids" | jq .
{
  "project": {
    "id": "e905aaf2bc7249e2916f3789f255ef8a",
    "name": "foo",
    "domain_id": "511b180417954e29bb03212a177f58bd",
    "description": "",
    "enabled": true,
    "parent_id": "c8364aeb843c485cab13a3ff77e3f4e5",
    "is_domain": false,
    "tags": [],
    "options": {},
    "parents": {
      "c8364aeb843c485cab13a3ff77e3f4e5": {
        "511b180417954e29bb03212a177f58bd": null
      }
    },
    "links": {
      "self": "http://192.168.122.96/identity/v3/projects/e905aaf2bc7249e2916f3789f255ef8a"
    }
  }
}

The impact of this is that include_limits also does not work, and so two-level limit hierarchies are broken.