Feature/bunny hop (#2647)

* `@0x/contracts-erc20-bridge-sampler`: Add TwoHopSampler + refactor

* `@0x/asset-swapper`: Refactor + add two-hop skeleton

* Round out two-hop support in asset-swapper

* Add BalancerSampler, use it for two-hop quotes

* Fix bugs discovered from simbot

* rebases are hard

* Add intermediate token to MultiHop source breakdown

* Fix market buy bugs

* Use hybrid on-chain/off-chain sampling for Balancer

* Another day, another rebase

* Update changelogs

* Address PR feedback, CI fixes

* Address more PR feedback

contracts/test-utils/src/test_with_reference.ts

@@ -144,7 +144,7 @@ function _getParameterNames(func: (...args: any[]) => any): string[] {
         .replace(/[/][/].*$/gm, '') // strip single-line comments
         .replace(/\s+/g, '') // strip white space
         .replace(/[/][*][^/*]*[*][/]/g, '') // strip multi-line comments
-        .split('){', 1)[0]
+        .split(/\){|\)=>/, 1)[0]
         .replace(/^[^(]*[(]/, '') // extract the parameters
         .replace(/=[^,]+/g, '') // strip any ES6 defaults
         .split(',')