ENHANCEMENT: Register a learner - check system

Summary

ENHANCEMENT: Register a learner - check system if not already registered on same day and hours

Content

NEW ENHANCEMENT - High priority

When registering a learner on an offering, the system should check that the learner is not already registered for another offering on the same day and hours (actually the system check only if it's on the same course, need to have this check also if it's an offering of different course)

When learner request the offering or when the Learning Specialist register the learner.
For ILT, it should block the registration.
If mass assignment, it should display a message telling that the registration is not possible for this specific learner because of a conflict.