As an admin, I want to be able to view and manage existing users, so I can delete accounts or change their information.

[XiovV]

Acceptance criteria:

• User management page (the "Users" nav item) should display all existing users, including the currently logged in admin
• The user management page should not be accessible by non-admin users
• Upon clicking on a user, the page for editing that user's settings should open
• The top bar in the edit user settings page should have the trash button for deleting a user