multiply reward display by stablevault pps

[MarcoWorms]

Currently on the data panel we show:
Rewards this week 70,102.54 crvUSD

But really, since rewards are wrapped in yearn vault, this figure displays the amount of yvcrvUSD.

The figure should be multiplied by the vault's PPS. and we should continue to denominate the amount in crvUSD (stablecoins are easier to reason about than vault shares).