HPCC-9165 - Allow XREF to run without suspending coalescer

Add configuration option to allow XREF to run without suspending/
resuming the coalescer.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #4254 from jakesmith/hpcc-9165

HPCC-9165 - Allow XREF to run without suspending coalescer

Reviewed-By: Gavin Halliday <gavin.halliday@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>