Use Database to Store Supported Assets

[zahin-mohammad]

Currently, we hardcode supported assets in supported.go

// TODO: Move these to a table in PSQL
func GetSupportedAssets() map[string]bool {
	return map[string]bool{
		"BTC":  true,
		"ETH":  true,
		"USDT": true,
		"USD":  true,
	}
}

By moving this to the database, we can easily create a script to update/remove supported coins (ex. top 100 coins).

[zahin-mohammad]

On the other hand, it makes it easier on local dev to have this just be go object. For the case of supporting other coins easily, we can make a script to create a go object just for prod/test/dev.