HPCC-11305 Add support for the compulsory attribute in packagemaps

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>
Merge pull request #5803 from afishbeck/compulsory

HPCC-11305 Add support for the compulsory attribute in packagemaps

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
Merge branch 'candidate-4.2.6' into candidate-5.0.0

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>