Fix bug for non-multiple block length in AES-GCM

[confuseSUN]

Fixed two issues:

• A round of counter block calculation was missing.
• In the final XOR encryption, we incorrectly used bitwise XOR; the correct operation should be bytewise XOR.

[Autoparallel]

@0xJepsen can you review this?

@confuseSUN I appreciate your contribution here by the way. Though, not to disappoint you, these circuits are nearly deprecated 😕

Would you like to help out here: https://github.com/pluto/noir-web-prover-circuits