Epic: Backend to enable user defined model

[ravenac95]

User story: I can create a new user-defined model, by copying and pasting some SQL from a notebook, manually trigger a job, and see the status with logs. (Reuven / Icaro)

• Attempt every 15 minutes with a daily cron setting per model

This is an epic track progress to a basic user defined model:

[linear]

OSO-1319