HPCC-10945 Eclccserver doesn't support aborting query compilation

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #5828 from richardkchapman/eclccserver-abort-handling

HPCC-10945 Eclccserver doesn't support aborting query compilation

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>