Initial corpus for sv2_noise_cipher_roundtrip

[Sjors]

Generated by running for about two hours on an AMD Ryzen 7950x (32 threads) with Ubuntu 23.10 using Clang 16.0.6 and libFuzzer.

I used --with-sanitizers=fuzzer. Merged using --m_dir into 1.3MB.

I'll do a longer run once https://github.com/bitcoin/bitcoin/pull/29346 has had more review.