update tslib, set import-helpers: false [helix-front]

[micahstubbs]

Issues

• My PR addresses the following Helix issues and references them in the PR description:

#2165

Description

• Here are some details about my PR, including screenshots of any UI changes:

https://www.npmjs.com/package/tslib

https://stackoverflow.com/questions/51732554/cannot-find-module-tslib?answertab=trending#tab-top

angular/angular-cli#13886

https://www.typescriptlang.org/tsconfig#importHelpers

Tests

• The following tests are written for this issue:

Tooling change only, no new tests.

Commits

• My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message"

Code Quality

• My diff has been formatted using helix-style.xml
  (helix-style-intellij.xml if IntelliJ IDE is used)

[micahstubbs]

CI failure appears to be an unrelated ZK issue:

45828 [ZkClient-AsyncCallback-Retry-206-localhost:2127] ERROR 
org.apache.helix.zookeeper.zkclient.callback.ZkAsyncRetryThread [] - Error retrying callback 
org.apache.helix.zookeeper.impl.client.TestZkClientAsyncRetry$MockAsyncZkClient$1@4278a9b7, 
cancelling it
org.apache.helix.zookeeper.zkclient.exception.ZkException: null

https://github.com/apache/helix/runs/7662436946?check_suite_focus=true

[micahstubbs]

This PR is ready to be merged, approved by @NealSun96

Final commit message:

update tslib, set import-helpers: false [helix-front] (#2166)

Ensure that consumers of helix-front do not themselves need tslib as a direct dependency.