Webpages do not detect we are logged in properly

[StefanVanDyck]

Currently our current state of authentication is not registered correctly in the portal.
This can be quite strange, for example, when downloading it will show us the input-field for submitting our e-mail adress, even though we just logged in.

Should be fixed by using a proper js library for managing our oidc token/states?
Especially need to make sure this works with the Downloads page, as requesting a download with a free-form email input field fails.
So we need to make sure we always redirect to a login form if people are not logged in, but trying to download.