HPCC-11693 Catch and handle OOM and failover when setting up HT

If it manages to avoid OOM on gather, but OOM's setting up sized
HT, then catch OOM exception coming back from roxiemem and let
it degrade to distributed local lookup join.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
I hadn't realized maxSpillCost effected whether allocate threw an exception or not.

I think it should not change exception handling, separate JIRA opened : https://track.hpccsystems.com/browse/HPCC-12031