[broker] get_instrument_trade_data()

[SeverinJB]

POST https://demo.trading212.com/rest/v2/account/instruments/settings

with ["DSHUSD", ...]

Response example:
[{"code":"DSHUSD","maxBuy":750.0,"maxSell":750.0,"maxOpenBuy":750.0,"maxOpenSell":750.0,"suspended":false,"minTrade":1}]

GET https://demo.trading212.com/rest/v1/tradingAdditionalInfo

URL encoding: ?instrumentCode=DSHUSD&positionId=null&quantity=750

Response example:
{"buyMargin":5212.28,"sellMargin":5212.28,"buySwap":-22.49,"sellSwap":0.00}