Make authentication component follow new solid-oidc

[sync-by-unito]

Analyse the code changes needed for the following spec changes.

• Solid_oidc_supported is no longer required in the well-known openid-configuration; discovery now happens by looking for "webid" in the "scopes_supported" instead.
• Tokens will now only include the "webid" claim if requested with a "webid" scope
• Instead of the access token webid will be included in the ID token
• This ID token needs to be exchanged for an access token at the solid server's authorization server. This server can be discovered by looking for the WWW-Authenticate HTTP header in response to an unauthenticated request, which will include an as_uri parameter

To keep backward compatibility, we should check if it is possible to use the www-authenticate header to detect if a server uses the old or new spec, and then act accordingly.

┆Issue is synchronized with this Wrike task by Unito

[lem-onade]

I think most of this is done by Inrupt's js library. Perhaps a good time to create our own login functions