Feature - A0xRouter - 0x swap fees removal #864
Description
The 0x api allows specifying swapFeeRecipient and swapFeeBps, with a maximum of 1000 bps. However, this fee defeats the principle that the pool operator cannot access pool's funds directly, because arbitrary fees could be used to empty the pool. The fee is encoded in the data field passed to the 0xSettler instance. This means we will have to decode the fee and assert it is null. This is a security enhancement, not a bug - because the pool operator is not fully trustless.