Add ability for coordinators to recreate attendance objects for a given day

[smartspot2]

When a section's date is changed to a new day of the week, the old section occurrences and attendances are not moved over; there are a couple possible solutions to this:

• Coordinators should have a button to re-create attendance objects for a given day directly on scheduler.
• When a section's date is changed, the students in the section should have their attendances changed as well.

The latter solution has a few points to consider: do we want to have all attendances moved over to the new section occurrences? Do we only want to move over future attendances? Or do we not want to move over anything at all, and only create new attendances for the new dates?

The former solution would be a good thing to have regardless, as a fail-safe for this scenario, along with other edge cases (i.e. students joined after the section date, but still need the attendance to be taken, etc.)