Feature request: enable JavaScript testing

[chx]

I have no idea how to get headless chrome running in github actions (to be fair it caused endless headaches locally as well). PR to get it running would be welcome. It should restore the following files:

3. tests/sut/bar/tests/src/FunctionalJavascript/JavaScriptTest.php
4. tests/sut/qux/tests/src/FunctionalJavascript/FieldBase.php
5. tests/sut/qux/tests/src/FunctionalJavascript/FieldFormatterTest.php
6. tests/sut/qux/tests/src/FunctionalJavascript/FieldWidgetTest.php

And revert 53d7c3a which commented out the generated test in xerox.

The previous maintainer said back in November phpunit just skipped these but it surely doesn't do that now.

[andypost]

probably it needs to switch to w3c driver https://www.drupal.org/node/3460567

[chx]

There's a lot more than that, it probably needs a selenium container -- without it I got a connection error -- I tried adding it and then I got a no capabilities available error message and that's where I gave up. Probably chromedriver is missing etc. Getting these tests running is certainly not the best use of my time, there's a lot to do.

[chx]

I started on this again the branch webdrivertest but got nowhere.