I'd missed another ES2015 feature in #11712 that causes element isDisplayed() errors in older browsers

This PR fixes #11716 which shows more info:

• [🐛 Bug]: Array.from() errors in older browsers via isElementDisplayed() #11716

Proposed changes

Due to missing Array.from() support in Internet Explorer, we should change element.childNodes loops:

  // If the container's overflow is not hidden and it has zero size, consider the
  // container to have non-zero dimensions if a child node has non-zero dimensions.
- return Array.from(element.childNodes).some(function (childNode: Element) {
+ return [].some.call(element.childNodes, function (childNode: Element) {

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• I have added proper type definitions for new commands (if appropriate)

Further comments

I've used npm link on this branch against our test suite and Internet Explorer 11 now works fully 🙌
https://app.saucelabs.com/tests/337440d31bba4b86bef79ad74120cd75?auth=df173806cff971e450b9c09008348705

Reviewers: @webdriverio/project-committers