Add protected routes and support additional roles
requested to merge oliviergoulet/membership.eclipse.org:protected-routes-and-useauth into dev-portal-admin
This is work going towards building the admin page.
It adds:
- ProtectedRoute component, which handles authentication and authorization
- Adds admin role support
- useAuth hook, I am thinking this will be temporarily used until we update how user state is managed (PortalContext is simply too huge at the moment).
- An error 401 page
- Jest support (tests weren't working before)