feat: new spike on a persisted pipeline pattern

[iloveagent57]

Alternatives considered:

• https://joeflow.readthedocs.io/en/latest/tutorial/workflow.html - too reliant on celery out of the box, no innate mechanism for persisting state of individual steps.
• https://docs.viewflow.io/overview/index.html - too complex for our needs, aimed at human-in-the-loop business workflow use-cases.

Merge checklist:

• ./manage.py makemigrations has been run
  • Note: This must be run if you modified any models.
    • It may or may not make a migration depending on exactly what you modified, but it should still be run.

Post merge:

• Ensure that your changes went out to the stage instance
• Deploy to prod instance