UMIP 59 -Add USD/UNI_V2_WBTC_ETH_LP, USD/UNI_V2_USDC_ETH_LP, USD/UNI_V2_UNI_ETH_LP, USD/UNI_V2_UMA_ETH_LP token price identifiers

The DVM should support price requests for the following Uniswap V2 LP tokens: WBTC-ETH, USDC-ETH, UNI-ETH, UMA-ETH.