RFC 697: Force-create settings insight migration jobs in oobmigrator

Created by: efritz

See RFC 697: Multiple version upgrades.

The jobs for insights jobs were created within a schema migration, but this table's data is not protected from squash (as it relies on other data and not canned rows). This means that only instances that have that original migration file (notably excluding the new version of the migrator service) for the jobs to exist.

Instead, we should add the jobs from the current settings values on startup of the migrator if the jobs do not already exist. This will slightly modify the out of band migrator interface (most likely the addition of a new public Init/Sync method on the interface).