user: Admin/Instructor User Mangement

[AndrewDoering01]

References: #11 As an Admin or Instructor, I want to be able to upgrade users to tutors, so that I can manage them separtely

Definition of Done

• [x] Admins and instructor will have a user management tab under their dashboard
• [x] Instructors will be able to search by name or username and manage a certain account
• [x] Instructors will be able to check an "is tutor" field
• [x] The status of that user will be moved from standard user to tutor in the DB

Tasks

• [x] #177
• [x] #198
• [x] #213
• [x] Create route guard for admin dash on frontend
• [x] #219
• [x] #225