Fix links to various sections in OID4VP + copyright year + some broken links

[jogu]

Incorrect JWE section link was pointed out by Martijn (thanks!)

[c2bo]

There seem to be more references for OpenID4VP that are broken (or rather got shifted). Another one I saw glancing over was:

• Response mode MUST be direct_post.jwt. The Verifier MUST return redirect_uri in response to the HTTP POST request from the Wallet, where the Wallet redirects the User to, as defined in Section 7.2 of [@!OIDF.OID4VP]. Implementation considerations for the response mode direct_post.jwt are given in Section 12.4 of [@!OIDF.OID4VP].

I believe those should be 8.2 and 14.3 (sorry, can't create comments on text outside of the scope of the PR).

[jogu]

Thanks @c2bo - I fixed those!