Extension request: Ability to get info about ETFs

[tsjk]

I'm a new user of this package and think it's awesome.
I'd like to have details on ETFs, though.
Currently, there is no route defined for ETFs, and just translating to enum to text yields the wrong url.
I currently hack my way around this (I <3 Python's stance here and allowing this) by doing like

avanza_._Avanza__call(HttpMethod.GET, '/_api/market-guide/exchangetradedfund/<id>')

and

avanza_._Avanza__call(HttpMethod.GET, '/_api/market-guide/exchangetradedfund/<id>/details')

where avanza is my Avanza object and HttpMethod.GET is from avanza.constants.
But it'd be nice to at least have a working route and some helper functions.

[tsjk]

/_api/market-guide/exchangetradedfund/<id> returns:

{
  "orderbookId": str,
  "name": str,
  "isin": str,
  "tradable": str,
  "listing": {
    "shortName": str,
    "tickerSymbol": str,
    "countryCode": str,
    "currency": str,
    "marketPlaceCode": str,
    "marketPlaceName": str,
    "tickSizeListId": str,
    "marketTradesAvailable": bool
  },
  "historicalClosingPrices": {
    "oneDay": float,
    "oneWeek": float,
    "oneMonth": float,
    "threeMonths": float,
    "startOfYear": float,
    "oneYear": float,
    "threeYears": float,
    "fiveYears": float,
    "tenYears": float,
    "start": float,
    "startDate": str
  },
  "keyIndicators": {
    "direction": str,
    "leverage": float,
    "numberOfOwners": int,
    "historicYield": float,
    "historicYieldDate": str
  },
  "quote": {
    "buy": float,
    "sell": float,
    "last": float,
    "highest": float,
    "lowest": float,
    "change": float,
    "changePercent": float,
    "spread": float,
    "timeOfLast": int,
    "totalValueTraded": float,
    "totalVolumeTraded": int,
    "updated": int,
    "volumeWeightedAveragePrice": float
  },
  "type": str
}

[tsjk]

...and avanza_._Avanza__call(HttpMethod.GET, '/_api/market-guide/exchangetradedfund/<id>/details') returns:

{
  "assetCategory": str,
  "category": str,
  "issuer": str,
  "description": str,
  "documents": {
    "kid": str,
    "prospectus": str
  },
  "orderDepthLevels": [
    {
      "buySide": {
        "price": float,
        "priceString": str,
        "volume": int
      },
      "sellSide": {
        "price": float,
        "priceString": str,
        "volume": int
      }
    },
    ...
  ],
  "brokerTradeSummaries": [
    {
      "brokerCode": str,
      "sellVolume": int,
      "buyVolume": int,
      "netBuyVolume": int,
      "brokerName": str
    },
    ...
  ],
  "fee": {
    "totalMonetaryFee": float,
    "totalPercentageFee": float
  },
  "trades": [
    {
      "buyer": str,
      "buyerName": str,
      "seller": str,
      "dealTime": int,
      "price": float,
      "volume": int,
      "matchedOnMarket": bool,
      "cancelled": bool
    },
    ...
  ],
  "tradingUnit": int,
  "collateralValue": float,
  "introDate": str,
  "ordersAndDeals": {
    "orders": [],
    "deals": [],
    "hasStoplossOrders": bool,
    "accounts": [
      {
        "accountId": str,
        "accountName": str,
        "accountType": str
      },
      ...
    ]
  },
  "dividends": {
    "events": [],
    "pastEvents": [
      {
        "exDate": str,
        "paymentDate": str,
        "amount": float,
        "currencyCode": str,
        "dividendType": str
      },
      ...
    ]
  },
  "fundExposures": [
    {
      "orderbookId": str,
      "name": str,
      "exposure": float,
      "instrumentType": str,
      "countryCode": str,
      "hasPosition": bool
    },
    ...
  ],
  "riskScore": str,
  "holdingPeriod": str,
  "countryExposures": {
    "updated": str,
    "exposures": [
      {
        "countryCode": str,
        "countryName": str,
        "weight": float
      },
      ...
    ]
  },
  "sectorExposures": {
    "updated": str,
    "exposures": [
      {
        "sector": str,
        "weight": float
      },
      ...
    ]
  },
  "portfolioDate": str,
  "esgView": {
    "euArticleType": str
  },
  "superInterestApproved": bool
}