Pages - /admin: Improvements

[prog-z-99]

• [ ] Add collapsible details to admin mentor lists for mods to check mentor work more easily.
  • [x] Move editable details (deleting buttons, mentor status, admin status, reviewer status, etc) Inside the collapse
• [x] Add mentor activity-related information to the admin table rows instead
• [x] Add tab to show current mentors only (was solved(?) by sorting all the active members first)