List run events

curl --request GET \
  --url http://localhost:8000/runs/{run_id}/events

{
  "events": [
    {
      "type": "<string>",
      "message": {
        "role": "<string>",
        "parts": [
          {
            "content_type": "text/plain",
            "name": "<string>",
            "content": "<string>",
            "content_encoding": "plain",
            "content_url": "<string>",
            "metadata": {
              "kind": "citation",
              "start_index": 123,
              "end_index": 123,
              "url": "<string>",
              "title": "<string>",
              "description": "<string>"
            }
          }
        ],
        "created_at": "2023-11-07T05:31:56Z",
        "completed_at": "2023-11-07T05:31:56Z"
      }
    }
  ]
}