Candidate CohortYear insufficient for candidates enrolled in multiple programs

Story 

Candidate CohortYear is not tied to any sort of education organization or program so when used by a system of schools (CSU as an example) you will not be able to easily distinguish what year the candidate was part of a given school if they end up enrolling at more than one school

Core has handled this by placing the CohortYear for students of the StudentEducationOrganizationAssociation