Add extra fiat currency pairs

Add as many new fiat currency pairs as we can conceivably support on a free price feed.

Or maybe use a paid feed?

Requested by Marius on Telegram.

https://github.com/willyfromtheblock/ppc-worker-price-update

https://peercoinexplorer.net/price-ticker

https://openexchangerates.org/

Requested: PEN (Peruvian Sol) by Telegram @bigplayermaster