feature: initialize db with restarting past continuous subscriptions.

[itsmostafa]

TEMPORARY: initialize all continuous subscriptions overdue to restart. This code will be removed once its successful in production

Note: temporarily commented out mypy from pre-commit due to this error:

error: Library stubs not installed for "pytz" (or incompatible with Python 3.8)

🗣 Description

💭 Motivation and context

🧪 Testing

tested locally

✅ Pre-approval checklist

• [x] This PR has an informative and human-readable title.
• [x] Changes are limited to a single goal - eschew scope creep!
• [x] All future TODOs are captured in issues, which are referenced in code comments.
• [x] All relevant type-of-change labels have been added.
• [x] I have read the CONTRIBUTING document.
• [x] These code changes follow cisagov code standards.
• [x] All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• [x] Tests have been added and/or modified to cover the changes in this PR.
• [x] All new and existing tests pass.