UMIP 65 -Add uTVL_KPI_UMA as a Price Identifier

Key Performance Indicator(KPI) options are synthetic tokens that redeem to protocol tokens with the redemption value determined by performance against that indicator. One example of a KPI is Total Value Locked (TVL).

This UMIP enables the DVM to support price requests based on the TVL of UMA

A synthetic option is minted against a base collateral, in this case UMA, which expires at 00.00(UTC) June 30th 2021.

Options are redeemed on the basis of TVL/10^9, with a floor of 0.1 and a ceiling of 2.