PhpUnit make test results more developer friendly

Patch #50 applied for me on Drupal 10.1.6

Before patch:
Time: 00:17.625, Memory: 6.00 MB
OK (4 tests, 46 assertions)

After patch
Time: 00:20.306, Memory: 6.00 MB
OK (4 tests, 46 assertions)

Re-roll for Drupal 11.1.x

#58 works well on Drupal 11.1.4

Haven’t reviewed but issue summary appears incomplete

@niklan That patch prints absolute paths to the HTML files, not URLs.

Updated patch to address #61.

Also, the path to HTML output is hardcoded:

$uri = $this->htmlOutputBaseUrl . '/sites/simpletest/browser_output/' . $html_output_filename;

Maybe we should try to resolve '/sites/simpletest/browser_output/' using str_replace($this->root, '', $this->htmlOutputDirectory), but I'm not sure how it is reliable.