Zap for crypto meta stable factory pools

[romanagureev]

ZapStableSwapFactoryOne

This version follows the same interface as others.

How to test it

brownie test tests/zaps/forked/ --deployed_data mainnet --zap_base stable_factory --network mainnet-fork

or mainnet-3 for base pool with 3 coins.

ZapStableSwapFactory

This version works for any level (up to) 1 meta pools.

Notes

Used [meta, base0, ..., base4] for each meta coin, so it is obvious how to exchange any coins and allows to add any combination of tokens like base coins along with their lp token.
Used 2 dimensional array as it makes implementation clearer and I looks like it is harder to make mistakes this way(e.g. writing from 5-th index for the second pool) .
If you give raw ETH with _use_eth=True when there are no with or eth in add_liquidity(...) it will not revert. To handle it, consumed ETH has to be handled on each step, I decided that it is overhead and ETH can be recovered via removing liquidity.
If you do not put _min_amounts for base coins in remove_liquidity(...) it will remove only lp. But if you put them, lp's _min_amount will be ignored.

How to test it

brownie test tests/zaps_factory/forked/ --deployed_data mainnet --network mainnet-fork