Feat: CalFresh re-enrollment error

[thekaveman]

Closes #1921.

Currently on top of #1968 since both of these PRs introduce migrations.

Currently on top of #1989 since both of these PRs work on the enrollment views.

Currently on top of #2053 since both of these PRs introduce migrations.

How to test

1. (Temporarily) override the value returned by session.enrollment_expiry() e.g.

   expiry = datetime(2024, 5, 31, tzinfo=timezone.utc).timestamp()
   if expiry:
       return datetime.fromtimestamp(expiry, tz=timezone.utc)
   else:
       return None

2. In the Admin, update a flow that you can pass eligibility for (e.g. MST Courtesy Cards): check supports expiration and add a value for the expiration days, re-enrollment days, and re-enrollment error template = enrollment/reenrollment-error--calfresh.html

3. Pass eligibility

4. Enter the path /enrollment/reenrollment-error

5. See the new re-enrollment error page

[github-actions]

Coverage report

Click to see where and how coverage changed

File	Statements	Missing	Coverage	Coverage (new stmts)	Lines missing
benefits/core
models.py
benefits/enrollment
views.py					134
Project Total

This report was generated by python-coverage-comment-action

[thekaveman]

Rebased on #2052

[thekaveman]

Rebased on #2053

[thekaveman]

I figure this can be reviewed and merged after #2053, similar to how we did for #1988.

This page won't be available until we explicitly turn it on for a flow, after completing #2062 where we can really test that it works with live data. Until then, it won't impact any production users.