Possible 63/64 vulnerability for liquidation callback

[arthurka-o]

From gas report, overlayMarketLiquidateCallback in ShivaV1 consumes maximum of 123036 gas. liquidate without a callback consumes around 181792 (not enough data for minimum value yet)
So to abuse 63/64, overlayMarketLiquidateCallback should consume more than 181792 * 64 = 11.634.688 which is x94 of the current max.

We need to keep in check gas consumption of overlayMarketLiquidateCallback (should NOT go up too much), and liquidate (should NOT go down too much)