Add currency names, icons

This could simply be a data entry task. In the grand scheme of things, there aren't **that** many cryptocurrencies out there. It's at least not beyond the scope of a data entry task for a few hours. Just manually entering a fixed set of cryptocurrency names to match ticker names in a data file would mean no API requests will be needed to fetch that information.

Iconography is important for identifying things easily. Icons should be added for all currencies.

Some currency/tokens parsed from Binance are relatively nonsensical. They should be purged from the database.