Fix for issue #1205 - Populated data source with label/values to avoid the need to parse student id out of label
Issue #956 - Tracking of record_event field for inclusing in subquery(in progress)
#956 - generate and attach subquery to base query
Fixed issue that caused the user search to fail #956
#956 - minor cleanup, resolved issue with erroneous triggering of subquery
Merge branch 'main' into usersearch_overlap
Fix a bug in some user searches

The 'subquery' variable used for combination list searches is referenced
outside the if-statement where it is initialized.  This moves the
initialization out of the if-statement to avoid an undefined reference if
the other branches are followed.
Merge pull request #1277 from learning-unlimited/usersearch_overlap

Fixes most common cases of #956.  Also includes fix for #1205.