Feature Request: Provide separate information for deposit / withdrawal status on each currency

[susemeee]

*this is a feature request.

• OS: -
• Programming Language version: -
• CCXT version: -

Current currency structure does not distinguish between 'depositable' and 'withdrawable' status. A lot of exchanges make some currencies depositable but not withdrawable, vice versa. Some exchange (particularly, Binance) provides two or more methods to deposit / withdraw the currency and not every methods may be usable at some time because of reasons like blockchain network issue.

I think adding depositActive and withdrawalActive property in each currency in addition to active might be a good start point. However, there maybe the case that those flag can't be determined, as I don't think every exchange would provide separate information for deposit and withdrawal.

I'm in process of adopting ccxt for ongoing project and lack of this feature made me to temporally use implicit API.

Thanks for great consolidation code for tons of different exchanges by the way.