Set up auth access levels for UI

[jescalada]

Is your feature request related to a problem? Please describe.
Related to #1. We want to make the admin routes only accessible by admins and make the rest of the routes, except the login page, accessible only by logged-in users.

Describe the solution you'd like
This will require some kind of wrapper component for all the routes and a hook to check if a user is currently logged in and their admin status.

Describe alternatives you've considered
None

Additional context
None