T2972
Depends on D13642
Add price info to messages sent by ecash-herald
A slight refactor was required to the getCoingeckoPrices function. We need coingecko's exact API response for unit test mocks. So, I return it.
Another option would be to separate getCoingeckoPrices into two functions. This was considered but dismissed as it is useful to get all the info from using your config.priceApi param.