We have hit a few 50x errors while pulling a page to get
links and that has caused the rest of the link checking to
terminate early. To fix that we switching to LogError which will
output an error in devops instead of Write-Error which terminates
immediately. We also add some retry count to the page retrieval
and cache file retrieval to help with these transitent 50x issues.
Co-authored-by: Wes Haggard <Wes.Haggard@microsoft.com>
