BalancerBridge (#2613)

* Add BalancerBridge and Sampler functions

* Update sampler artifacts/wrappers

* Add Balancer support to AssetSwapper + related refactoring

* Make use of GraphQL instead of sampler

* "fix" build and add mainnet BalancerBridge tests

* address some comments

* add balancer cache and fix DexSampler tests

* lint

* wip: tests for balancer sampler ops

* Fix market operation utils test

* balancer unit tests

* Return a buy quote of 0 if the buy amount exceeds the Balancer pool's balance

* Dynamic fee estimation

* Update contract addresses, export BalancerBridge wrapper

* Update changelogs

* Fix bugs discovered via simbot

* Fix issues in balancer_utils

* override `BigNumber.config` in configured_bignumber.ts

* Special case Balancer subops in  too

* Address some more comments

* Address Balancer performance issue

* Performance improvements

* Address comment

* Fix tests

Co-authored-by: xianny <xianny@gmail.com>

packages/migrations/src/migration.ts

@@ -379,6 +379,7 @@ export async function runMigrationsAsync(
         maximumGasPrice: NULL_ADDRESS,
         dexForwarderBridge: NULL_ADDRESS,
         multiBridge: NULL_ADDRESS,
+        balancerBridge: NULL_ADDRESS,
         exchangeProxyGovernor: NULL_ADDRESS,
         exchangeProxy: exchangeProxy.address,
         exchangeProxyAllowanceTarget: exchangeProxyAllowanceTargetAddress,