Add the max number of decimals to Currency #1125
Description
Why - Problem description
In the prices API they limit the number of decimals to 2.
But there are (rare) currencies with 3 decimals.
What - Proposed solution
The prices API should accept prices with up to 3 decimals.
Here in off-dart we should add the max number of decimals as a Currency field.
The default would be 2, and for 7 currencies it would be 3 - to be verified.