- Expanded output from guest info api endpoint
- Share guest info between both routes under /sponsor of the frontend.
- More localised text options added for use on the sponsor pages
- Details button on the sponsor overview page now points to the guest
  info page for each person.

Resolves: GREG-74

Issue: GREG-72

- Only clear info on 401
- Move the fetch to the provider.

Issue: GREG-72

Issue: GREG-72

- Better loading of translations using suspense.
- Adds a "fetched" variable to the user objects. Enable us to show a
  spinner before the return of the userinfo call

Issue: GREG-72

- Introduces the Invitation and InvitationLink models for keeping track
  of guest invitations and the links connected to them.
- Adds a post endpoint accessible by sponsors to create invitations for
  guests.
- Adds a get endpoint for the guests to review their invitation
  information.
- Adds a post endpoint for the guests to confirm their invitation with
  updated mobile_phone number if they want.
- Removes token field from Person since it is not used.

Make all URLs relative. Move /oidc and /admin endpoints up from /api and proxy them during development.

The UserContext is used to "protect" routes

Issue: GREG-70