test: E2E test flows + new app harness

[aarongranick-okta]

E2E tests with coverage on:

• signin
• getWithRedirect
• getWithPopup
• renewToken
• getTokenWithoutPrompt
• getUserInfo
• okta hosted flows, both PKCE and implicit
• direct login, using sessionToken

Adds an improved test harness app

[haishengwu-okta]

LGTM.
but curious how we made decision to use wdio.js instead of testcafe which has been used in many products today.

[pradeepdewda-okta]

Why the testcafe is not used?

[aarongranick-okta]

@haishengwu-okta @pradeepdewda-okta I was not aware there was a decision/direction to use testcafe. I'm sure the tests could be rewritten to use testcafe, I'm curious what would be the advantage?

[richardheng-okta]

We are using TestCafe for the sign-in-widget, my-okta, Azuqua and for Courage e2e. I strongly recommend using it over Selenium because of its several automatic anti-flakiness features.
Here is a document that outlines some of the reasoning:
https://oktawiki.atlassian.net/wiki/spaces/eng/pages/641499764/TestCafe+in+okta-ui

The biggest advantage I see personally is that you don't have to write any more 'waitFor' code before interacting with elements like this:
https://github.com/okta/okta-auth-js/pull/256/files#diff-669f14e7b65486de90052f44e8a2a2a0R86

If you have any questions, feel free to reach out.

[aarongranick-okta]

@richardheng-okta FYI: I have started working on converting the tests to testcafe. I think I have hit a blocker, which is support for popup windows. Apparently testcafe can only run in a single window so all popups and links are opened in the same window. This will not allow us to properly test our login flow which uses a popup and message communication between the windows. DevExpress/testcafe#912

@robertjd I think it may be best to merge this PR, with webdriver IO tests. We can add an item on backlog to convert to testcafe when/if support for multiple windows is added. (Although the issue is 3 years old, it appears they ARE working on it)

[richardheng-okta]

@aarongranick-okta That seems reasonable to me. Thanks for looking into it!