Smarter gas estimation

There was a previous issue with the keeper acl where web3py / brownie couldn't accurately estimate gas for meta contract calls (ie keeper acl's contract's harvest function calls the strategy harvest function calls convex staking gauges claim calls...). In order to quick fix this we set manual gas limits for each chain / tx type. This led to issue on FTM where oxd vault calls are more expensive due to underlying actions taken in their contracts, so want to have smarter gas estimation to be more robust.