PIP-15: Increase Base TVL

Abstract Increase the base TVL for eligible NFT collections from 32% to 35%.

Background Eligible NFTs can borrow up to 32% of their value with liquidation occurring at 33%. This proposal would increase the max LTV to 35%. Liquidation would occur at 36% LTV, or 43% if a user has a JPEG Card with cigarette attribute deposited.