wert.io integration

[anonymoussprocket]

Modify the implicit account balance banner to include a link to wert.io for tezos purchases with a credit card. Use this as examples of how it might work: A, B.

[anonymoussprocket]

perhaps use clicks on the "USD", "EUR", "JPY" labels as a trigger: https://github.com/Cryptonomic/T2/blob/trunk/src/components/BalanceBanner/index.tsx#L153

[Nike682631]

1. Wert is a fiat gateway allowing a user to buy crypto with a credit/debit card and have it deposited automatically into his account.
2. The user click on buy tz next to the balance and will be redirected to the wert site in an external browser. Data is not being stored.