update nimbus-jose-jwt dependency to 2.26 and fix the affected files

I made some changes. Please review it.
This is supposed to be the key ID, not the Algorithm -- please change the line to:

```java
JWK jwk = new OctetSequenceKey(Base64URL.encode(key), KeyUse.SIGNATURE, null, null, id, null, null, null);
```

(Note: I haven't tested this change, just checked against the documents for Nimbus)