feat: manager should be aware of new enrollments after last export

[hgg]

Expected Behavior

The admin dashboard should have a section warning the admin about new, unprocessed registrations, allowing him to attend to those cases.

Current Behavior

Currently the admin has no way to know if any new registrations happened in the platform.

Possible Solution

My suggestion would be a visible warning in the main screen of the admin dashboard, perhaps with a section in the dashboard that allowed exporting and importing the necessary files with the required information to fix the issue.

Context

With this feature, a simpler and direct way of dealing with new registrations would be available, preventing misunderstandings and delays in the whole process for which the platform was made. Also, this follows the line of thought of #2, since after removing the overlap restriction, the admin will be needing to constantly check for new registrations and treat them, which right now has to be done by waiting for students to contact him about the situation.