Prompted by issue #1035, add tests to detect pages not listed with href in toc and/or unresolved link to page
If topicHref is used in a toc.yml file as a heading for child items, one of those children should be a href to the same file. Otherwise the page's content will be displayed in the toc area.
"for TopicHref referenced by TOC file" / "for Href referenced by TOC file" : file not found during build (results in broken link)
Description
Prompted by issue #1035, add tests to detect pages not listed with href in toc and/or unresolved link to page