Implement authorization that restricts Teacher users view to only their specific classes

[JAYKAY2291]

Summary

Teacher users should only be able to see their own class of student users' information.

Things out of Scope

Admins do not need restriction and should be able to view all students. Altering student view is also out of scope.

Criteria for Completion

• When a Teacher user goes to view students they should only be able to see students in their predefined classes.
• This feature should only be available to Teachers
• Add a test proving that it works