HPCC-10349 Initial version of the performance regression suite

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-10349 More tests, and better abort support

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-10349 Join, hash aggregate and csv/xml tests

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-10349 Allow number of iterations to be specified

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-10349 Add extra variants of the append tests

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-10349 Add some code to summarise the results.

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>