Modify Permission to See Poster's Name

[kmehta5]

Instructors can see the names of all posts, including anonymous posts; but students can only see the names on non-anonymous posts and their own anonymous posts.
Estimated effort for each task: Large
Dependencies among tasks: None - understanding existing permissions
Milestones to indicate which sprint the issue should be completed in (Sprint 1, Sprint 2, Stretch): Sprint 1
Acceptance criteria that describes how you know this task is done - think about how you will test this feature: Use different user account to check if they have the right permissions.