Add advisor and manager relationship to teacher candidates elements

Relationship 1: Advisor relationship to the teacher candidates

Teacher Candidate domain does not have a way to associate the candidate with staff members that may be their advisor, mentor, or professor in our program. Given the complexity of our program, associating the teacher candidate with staff will address the majority of our use cases since we need to see how our staff (aka professors) impact the teacher candidates in their class.  Professors of our program use this relationship to determine how effective their teaching is to their students (in this case Teacher Candidates in our program). Including this feature not only will improve how we determine which teachers had which professors during their time in our graduate program, but it will also help empower us to understand the impact of the curriculum on k-12 students as a product of having xyz professor/advisor. E.g. Staff -> Advisor -> Teacher Candidate  

Relationship 2: Adding Manager element into the Staff Domain

The staff domain currently does not have a way of capturing manager level information associated with staff. We use this data as a way to group staff (in this case our professors) and their connection to who they're being managed by in our program. For example, the dean of our program will need to be associated with several professors. This will allow the dean who manages several professors to know the overall impact they have had on the teacher candidates in their class. E.g. Manager -> Staff -> TeacherCandidate.