Web: move {% endif %} to the right place

The end of the if block determining whether there is a log to
show was in the wrong place.
Web: create a single dictionary for all log files

Now get the file listing for the log directory only once, and then
look for recognised log types in it.  Return a separate file name
and URL so that it is not necessary to display the complete URLs on
the job information page.
Web: add ingestion log to job information page
Web: extract get_log_files function
Web: use new get_log_files function on job QA page

This removes the duplication of the log file handling code
between the job information and QA pages.
Web: update link to job info pages to match logs

It now says "job information" in lower case so that it looks less
out of place next to the log file names.