Added mantis-swap dex integration

[oogway112]

Background: Mantis Swap is a single-sided AMM for trading pegged assets that provides better capital efficiency and lower slippage to traders and utilizes an autonomous loss protection mechanism to reduce principal loss for liquidity providers.

Pricing logic: We use Asset-Liability model to calculate slippage during a swap. Detailed explanation in https://docs.mantissa.finance/mantis-scroll/amm-model

Documentation: https://docs.mantissa.finance/

Contract Addresses: https://docs.mantissa.finance/developer/contracts-and-wallets

Additional notes:

This integration has mostly used code from the Platypus integration since our model is similar but our mathematics and smart contracts are different.