Investigate PG 12+ CTE materialization

[ukd1]

Re:https://github.com/bensheldon/good_job/issues/65#issuecomment-1722391921

We need to investigate CTE materialization - we're expecting the default to be ok, but should test that vs explicitly on or off too and pick the fastest.

• [ ] test perf for default
• [ ] test perf for on
• [ ] test perf for off
• [ ] depending on results, decide if we push support min to PG 12, or introduce specific queries for > pg 12