Endpoint to list worker versions on a corpus

We need an endpoint to list all worker versions used on a corpus. Ideally with an element count annotation:

[
  {
    "id": "XXX",
    "worker": {
      "id": "YYY",
      "name": "tesseract",
    },
    "revision": {
      "id": "ZZZ",
      "revision": "deadbeef",
      "refs": []
    }
    "nb_elements": 142,
  ]
}

This would be used for ML stats & worker version selection on a corpus