List documents awaiting classification review

curl --request GET \
  --url https://api-sandbox.featherhq.com/v1/knowledge-base/knowledge-bases/{kb_id}/classification/pending \
  --header 'x-api-key: <api-key>'

{
  "items": [
    {
      "document_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "title": "<string>",
      "sensitivity": "<string>",
      "sensitivity_level": 123,
      "classification_status": "<string>",
      "classification_confidence": 123,
      "classified_at": "2023-11-07T05:31:56Z",
      "detected_sensitivity": "<string>"
    }
  ],
  "has_more": true,
  "next_cursor": "<string>"
}