List Entity Positions

curl --request GET \
  --url https://api.prime.coinbase.com/v1/entities/{entity_id}/positions

{
  "positions": [
    {
      "symbol": "BTC",
      "long": "10",
      "short": "10",
      "position_reference": {
        "id": "e8bbed13-fa33-41de-86d5-4335d8f08166",
        "type": "POSITION_REFERENCE_TYPE_UNSPECIFIED"
      }
    }
  ],
  "pagination": {
    "next_cursor": "<string>",
    "sort_direction": "DESC",
    "has_next": true
  }
}