Add 0.8 migration (#278) * feat: upgrade contracts to solidity 0.8 * feat: continue with 0.8 migration - Remove audits - Remove NFTDescriptor stuff because couldn't easily work through a weird assembly stacktoodeep issue. I think it has to do with ABIcoderv2 * fix: package.json * fix: tests for 0.8 migration * fix: clean up comment * feat: upgrade to 0.8.15 * fix: bump version * Fix code style issues with Prettier * fix: improve gas for liquidityamounts * Fix code style issues with Prettier * fix: review comments - add back nft descriptor tests - remove xits - improve ticklens gas * Fix code style issues with Prettier Co-authored-by: Lint Action <[email protected]>