UniswapV3 [TKR-4] (#197)

* add balancer v2

* fetch balancer v2 pools from subgraph

* feat: initial stab at a Balancer V2 Sampler WIP

* feat: add sampling for buys and fix build issues WIP [untested]

* fix: BalancerV2Sampler implementation issues, works on Kovan

* chore: BalancerV2 sampling boilerplate

* fix: update Balancer V2 mainnet address

* fix: consolidate differences between the 2 working branches

* fix: use mainnet Balancer V2 subgraph

* fix: stack too deep by minimizing and inline Balancer V2 vault interface

* fix: address review comments and clean up

* fix: sampler vault interface and pools cache assuming a pool has swaps

* address more review comments

* fix: TS type issues and add a comment about deadline argument

* fix: pools_cache_tests incorrect token addresses, prettier incompat

* fix: make ERC20BridgeSampler support BalancerV2 non view sampler fns

* fix: use a struct for passing encoded bridge data for Balancer V2

* chore: add changelog entries

* fix: improve gas accuracy of gas schedule for Balancer V2 & Maker Psm

* fix: don't exclude sources with stale caches & wait for cache refresh

* rebase

* `@0x/asset-swapper`: Fix stack too deep errors in sampler

* `@0x/asset-swapper`: Add uniswap V3 sampler.

* `@0x/contracts-zero-ex`: Add UniswapV3 support to FQT

* `@0x/protocol-utils`: Update BridgeProtocols.
`@0x/asset-swapper`: Add sell integration for UniswapV3.

* `@0x/asset-swapper`: Remove unnecessary swap quote consumer constructor arg.
`@0x/asset-swapper`: Enable UniswapV3 on ropsten.

* `@0x/asset-swapper`: UniswapV3 fixes

* `@0x/asset-swapper`: Fix stuff based on latest deployed testnet contracts

* `@0x/asset-swapper`: Remove UniV3 from mainnet sources for now

* `@0x/asset-swapper`: Tweak univ3 gas schedule

* fix CI?

* `@0x/contracts-test-utils`: Set default ganache gas limit to 100e6

Co-authored-by: xianny <xianny@gmail.com>
Co-authored-by: Kim Persson <kimpersson88@gmail.com>
Co-authored-by: Lawrence Forman <me@merklejerk.com>
Co-authored-by: Jacob Evans <jacob@dekz.net>

contracts/test-utils/src/web3_wrapper.ts

@@ -20,6 +20,7 @@ export let providerConfigs: Web3Config = {
     shouldUseInProcessGanache: true,
     shouldAllowUnlimitedContractSize: true,
     hardfork: 'istanbul',
+    gasLimit: 100e6,
     unlocked_accounts: [
         '0x6cc5f688a315f3dc28a7781717a9a798a59fda7b',
         '0x55dc8f21d20d4c6ed3c82916a438a413ca68e335',