Revert "Upgrade to jest 25 (facebook#17896)"

This reverts commit cf00812.

The changes to the test code relate to changes in JSDOM that come with Jest 25:

* Several JSDOM workarounds are no longer needed.
* Several tests made assertions to match incorrect JSDOM behavior (e.g. setAttribute calls) that JSDOM has now patched to match browsers.
  * https://codesandbox.io/s/resets-value-of-datetime-input-to-fix-bugs-in-ios-safari-1ppwh
* JSDOM no longer triggers default actions when dispatching click events.
  * https://codesandbox.io/s/beautiful-cdn-ugn8f
* JSDOM fixed (jsdom/jsdom#2700) a bug so that calling focus() on an already focused element does not dispatch a FocusEvent.
* JSDOM now supports passive events.
* JSDOM has improved support for custom CSS properties.
  * But requires jsdom/cssstyle#112 to land to support webkit prefixed properties.

Author: acdlite