HPCC-12333 Update unit tests to support different page sizes

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #6481 from ghalliday/issue12333

HPCC-12333 Update unit tests to support different page sizes

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>