Add Efinity and Westfinity SS58 address prefix (#48)

* Add Efinity and Westfinity SS58 address prefix

Hello everyone,

The Enjin team would like to add our SS58 prefixes for Efinity (Polkadot) and Westfinity (Westend).
Project website: efinity.io

Thank you!

* Updated order, removed Westfinity (testnet) prefix