[Cagalog] Enrollable status update based on enrollment dates

[brie_ubc]

Problem statement:

In the Catalog listings view, the "enrollable" column is misleading. A listing can be toggled as open for enrollment, but the enrollment start and end dates make it so it is unenrollable, and the "enrollable" column will still show a checkmark.

Proposed solution:

I would propose that the "enrollable" column has three states - a checkmark for enrollable listings, a blank or an "X" for unenrollable listings, and the orange calendar icon for a listing that is toggled to enrollable but is outside of its open dates.

User role(s):

admin