Submit job immediately on insertion?

[hjoliver]

User request: if a task is inserted with a cycle point earlier than current active cycle points, the intention is usually to re-run an old task, but its prerequisites can't be satisfied in-suite because the suite has moved on. So it would be useful to have an option to submit the inserted job immediately, to avoid the need for subsequent manual triggering. IMO there's probably no need to compare the cycle point against the rest of the suite - just select run-on-insert if that's what's needed, regardless of cycle point.

[hjoliver]

Note in light of #2654, this could be solved automatically: if you insert a task and its prerequisites have been removed from the suite, look up their completion status in the database.

Further, we eventually want to do away with concept of "insertion" - #2143

[hjoliver]

Fixed by spawn-on-demand #3515