HPCC-11886 Add classes to the performance tests to allow subsets to be run

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #22 from ghalliday/issue11886

HPCC-11886 Add classes to the performance tests to allow subsets to be run

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>