✨ Allow additional addresses to be added to infinite allowance for erc20

[moodysalem]

you can change the _givePermit2InfiniteAllowance() function to doesAddressHasInfiniteAllowance(address spender) returns (bool) and in the default implementation return spender == PERMIT2

this makes it simple to add to this list

[Vectorized]

This might break the compile-time zero-cost abstraction.

[moodysalem]

if it does that's solidity's fault (i understand this is referring to transferFrom), and either way worth it for cases where you want to have a few contracts automatically approved for ux and gas efficiency