Add a KUnit test suite for the AES-GCM library API.
It consists of:
- All the shared test cases from aead-test-template.h. These include
extensive consistency tests, a "Monte-Carlo test", and a benchmark.
- Tests against hardcoded AES-GCM test vectors from external sources.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://patch.msgid.link/20260802233005.161467-6-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>