User should be able to switch asset display currency to view its approximate value in selected currency

[dnaidionov]

When user selects different currency on the "View as" selector , following actions happen:

1. Asset value in its original currency is displayed deemphasized, and its value in newly selected currency is displayed as title.
2. Asset value graph is redisplayed in selected currency

New values are calculated based on the exchange rate from Cryptocompare API (cached by the hub for future use).

The rest of the Asset card is unaffected by the change

[habdelra]

This functionality is there now. I'm gonna assign to @burieberry for the styling work