orderbook and trade_preimage RPC improvements.

[artemii235]

Add more info to orderbook response for charts. Display UTXO fee to spend the payment in trade_preimage response.
#859 #872

[Milerius]

Is this utxo fees included in the total too ?

[sergeyboyko0791]

Thank you for these improvements. Could you please just make a few changes?

[artemii235]

Is this utxo fees included in the total too?

@Milerius Yes, please note that the coin's balance should not be checked for this case. There will be a paid_from_trading_vol flag indicating this, e.g.:

{
  "coin":"RICK",
  "amount":"0.00001",
  "amount_fraction":{
    "numer":"1",
    "denom":"100000"
  },
  "amount_rat":[[1,[1]],[1,[100000]]],
  "paid_from_trading_vol":true
}

So if paid_from_trading_vol is true you should display the fee but skip the RICK balance check.

[artemii235]

@sergeyboyko0791 As discussed in person, I've added the TotalTradeFee struct with the required_balance field. It covers the QRC20/QTUM trade - in this case, users will require QTUM balance to send their payment, and some QTUM will be deductible from trading vol. So it's impossible to properly set the paid_from_trading_vol for the total fee.

Please review the PR again when you have time 🙂

[sergeyboyko0791]

Looks good! Approve it :)