HPCC-12114 Ensure testing lower cased hint id's

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #6362 from jakesmith/hpcc-12114

HPCC-12114 Ensure testing lower cased hint id's

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>