Encrypt/Decrypt many TLS records at once

[th4s]

Currently our 2PC aead implementation encrypts/decrypts TLS records one by one. This incurs some roundtrip overhead because prover and verifier/notary have to exchange messages for this. It would be favorable to batch the en/decryption and process more than one TLS record at a time.

[sinui0]

One challenge with this that I didn't initially see is how this feature interfaces with the tls client. The TLS client is designed to process one record at a time, so we would have to take a look at what is needed there to pass them to our backend in batches.