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

contracts/staking/test/unit_tests/protocol_fees_test.ts

@@ -3,11 +3,10 @@ import {
     constants,
     expect,
     filterLogsToArguments,
-    hexRandom,
     Numberish,
     randomAddress,
 } from '@0x/contracts-test-utils';
-import { BigNumber, StakingRevertErrors } from '@0x/utils';
+import { BigNumber, hexUtils, StakingRevertErrors } from '@0x/utils';
 import { LogEntry } from 'ethereum-types';
 import * as _ from 'lodash';
 
@@ -56,7 +55,7 @@ blockchainTests('Protocol Fees unit tests', env => {
 
     async function createTestPoolAsync(opts?: Partial<CreateTestPoolOpts>): Promise<CreateTestPoolOpts> {
         const _opts = {
-            poolId: hexRandom(),
+            poolId: hexUtils.random(),
             operatorStake: getRandomInteger(minimumStake, '100e18'),
             membersStake: getRandomInteger(minimumStake, '100e18'),
             makers: _.times(2, () => randomAddress()),