Remove assetDataUtils everywhere (#2373)

* remove assetDataUtils everywhere

* export IAssetDataContract from @0x/contract-wrappers to allow @0x/instant to decode asset data  synchronously

* export generic function `decodeAssetDataOrThrow` and add ERC20Bridge support

* export `hexUtils` from order-utils instead of contracts-test-utils

test/order_prune_utils_test.ts

@@ -3,7 +3,6 @@ import { DevUtilsContract, ERC20TokenContract, ExchangeContract } from '@0x/cont
 import { constants as devConstants, getLatestBlockTimestampAsync, OrderFactory } from '@0x/contracts-test-utils';
 import { BlockchainLifecycle, tokenUtils } from '@0x/dev-utils';
 import { migrateOnceAsync } from '@0x/migrations';
-import { assetDataUtils } from '@0x/order-utils';
 import { SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import * as chai from 'chai';
@@ -70,13 +69,15 @@ describe('OrderPruner', () => {
         [makerTokenAddress, takerTokenAddress] = tokenUtils.getDummyERC20TokenAddresses();
         erc20MakerTokenContract = new ERC20TokenContract(makerTokenAddress, provider);
         erc20TakerTokenContract = new ERC20TokenContract(takerTokenAddress, provider);
-        [makerAssetData, takerAssetData, wethAssetData] = [
-            assetDataUtils.encodeERC20AssetData(makerTokenAddress),
-            assetDataUtils.encodeERC20AssetData(takerTokenAddress),
-            assetDataUtils.encodeERC20AssetData(contractAddresses.etherToken),
-        ];
         exchangeContract = new ExchangeContract(contractAddresses.exchange, provider);
         devUtilsContract = new DevUtilsContract(contractAddresses.devUtils, provider);
+
+        [makerAssetData, takerAssetData, wethAssetData] = [
+            await devUtilsContract.encodeERC20AssetData(makerTokenAddress).callAsync(),
+            await devUtilsContract.encodeERC20AssetData(takerTokenAddress).callAsync(),
+            await devUtilsContract.encodeERC20AssetData(contractAddresses.etherToken).callAsync(),
+        ];
+
         // Configure order defaults
         const defaultOrderParams = {
             ...devConstants.STATIC_ORDER_PARAMS,