Add dataset URL to the data product model in vreapi

We already have data_url in the model:

GET /vre-api/api/dataprods/

HTTP 200 OK
Allow: GET, POST, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

[
    {
        "uuid": "c97f0871-46f7-4601-9518-6b678c58b046",
        "created": "2023-11-09T15:03:17.824547Z",
        "title": "test",
        "description": "test",
        "data_url": "https://example.org/",
        "vlab": 3,
        "workflow": null
    }
]

QCDIS / VREPaaS

Add dataset URL to the data product model in vreapi #178