PQ - add additional utility to dump a page

See #6567 ands #6553

If we can use cpdump to find the page or if the page info is added to the error then we need to be able to look at the first event in that page.

Start by reading issues #6567 and #6553 for the page-identification and error-reporting context. Then trace the existing cpdump utility and its page-dumping entry point; the completed work should let an operator locate a page and inspect its first event.

Written by the indexing model from the issue text.