HPCC-9496 PackageMap Validate not checking RefFileInPackage flag

Currently lists all files in query rather than only those that are
not defined in the given packagemap.

Signed-off-by: Anthony Fishbeck <Anthony.Fishbeck@lexisnexis.com>
Merge pull request #4515 from afishbeck/packagemapValidateCheckFlag9496

HPCC-9496 PackageMap Validate not checking RefFileInPackage flag

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>