feat(tls/tests): move and adapt TLS tests into alknet-tls
Phase 1, Task 4 of crate extraction. Moves 34 tests into alknet-tls:
- server.rs: 16 tests (RawKeyCertResolver, SelfSignedCert, AcmeDirectory,
TlsServerConfig, build_rustls_server_config, build_quinn_server_config,
AcceptAnyCertVerifier)
- client.rs: 10 tests (FingerprintPinVerifier, select_server_verifier,
build_client_auth, TlsClientConfig::new + for_quinn)
- signing.rs: 6 tests (Ed25519SigningKey trait impls)
- pem.rs: 3 tests (load_cert_chain, load_private_key error paths)
build_quinn_client_config tests adapted to use TlsClientConfig::new().for_quinn().
tls_setup_x509 test adapted to use TlsServerConfig::new().
Test helpers (build_ed25519_spki_der, build_x509_cert_der, aws_lc_rs_provider,
verify_pin) moved with their tests.
Old tests stay in endpoint.rs and call_client.rs (duplicated). No breakage.
deepseek-v4-pro
b749fa8019