Calculating fixed delivery quotes for different asset scales results in wrong exchange rate

[mkurapov]

Bug description

When we are getting local quotes for a fixed delivery amount (i.e. in the cases where we have an incoming amount on the incoming payment, or have specified a receiveAmount in the quote request) across two different asset scales, we are incorrectly inverting the exchange rate:

This is the result of getting a quote from asset scale 2 to asset scale 9:

The quote from the above should instead be a 10:
100,000,000 (scale 9) -> 10 (scale 2). Moving the decimal place 7 places