Add support for SmartContractAddress field in CoinInfo

[monsieurleberre]

✨ Feature request

Add a string field to the CoinInfo to allow retrieving smart contract address when available

📝 Description

Currently, the field doesn't exist so the JSON data is not deserialized into the CoinInfo object

Describe the solution you'd like

Simply add a string field with the correct name on the class

Describe alternatives you've considered

Nothing really, apart from setting the field to null when the API returns "N/A", but this is not done anywhere else in the code