chore: update expected metadata with null published times

[inhumantsar]

While working on a separate issue, I ran node generate-testcase.js all to make debugging a little easier and noticed many testcases hadn't been updated to include publishedTime when it would result in a null value.

This PR adds those null values and apparently removes a newline from the visibility-hidden test case.

[fchasen]

Thanks so much for adding that to so many tests.