List open positions

{
  "error": "<string>",
  "pagination": {
    "limit": 123,
    "order": "<string>",
    "page": 123,
    "total": 123
  },
  "result": [
    {
      "entry_price": 123,
      "fair_price": 123,
      "id": "<string>",
      "liquidation_price": 123,
      "margin": 123,
      "market_id": "<string>",
      "notional": 123,
      "profile_id": 123,
      "side": "<string>",
      "size": 123,
      "unrealized_pnl": 123
    }
  ],
  "success": true
}