FrodoKEM test key material for wolfSSL tests.

IMPORTANT - these files are NOT generated by OpenSSL.

FrodoKEM is a Key Encapsulation Mechanism (KEM). Neither OpenSSL nor the
liboqs oqs-provider expose it as a certificate / key-encoding algorithm with
the ISO/IEC 18033-2 key OIDs (arc 1.0.18033.2.2.7.x) that wolfSSL uses - their
FrodoKEM support is KEM-only, for TLS key exchange, and is not going to be
present as a signature/certificate algorithm. So, unlike the ML-DSA material
in certs/mldsa/ (produced with OpenSSL 3.5+), these fixtures are generated by
wolfSSL itself using wc_MakeCert_ex() / wc_MakeCertReq_ex().

A KEM public key cannot sign, so the certificate and the request are signed by
an ECC (P-256) issuer key; the FrodoKEM key is only ever the subject public
key.

Files (material is provided for parameter sets N in {976, 1344}; the 640 set
has no standardised OID and cannot be encoded):
  gen_frodokem.c              Generator (the "regeneration" tool; see below).
  frodokem-ca-ecc-key.der     ECC P-256 issuer (CA) private key (DER / PEM).
  frodokem-ca-ecc-key.pem
  frodokem-ca-ecc-cert.der    Self-signed ECC issuer (CA) certificate.
  frodokem-ca-ecc-cert.pem
  frodokem<N>-key.der         FrodoKEM-<N> (SHAKE) private key, PKCS#8.
  frodokem<N>-key.pem
  frodokem<N>_pub-spki.der    FrodoKEM-<N> public key, SubjectPublicKeyInfo.
  frodokem<N>-cert.der        FrodoKEM-<N> leaf certificate signed by the ECC
  frodokem<N>-cert.pem        CA (subject key is FrodoKEM, signature is ECDSA).
  frodokem<N>-req.der         FrodoKEM-<N> certificate request (PKCS#10),
  frodokem<N>-req.pem         signed by the ECC key.

Regenerating:
  wolfSSL must be built with (at least):
    --enable-experimental --enable-frodokem --enable-certgen --enable-certreq
    --enable-certext --enable-keygen --enable-ecc
    CPPFLAGS="-DHAVE_PKCS8 -DWOLFSSL_DER_TO_PEM"
  then:
    cc gen_frodokem.c -lwolfssl -o gen_frodokem
    (cd certs/frodokem && ./gen_frodokem)

  The keys are generated fresh each run, so the output bytes differ every time;
  the committed copies are a stable snapshot for the test suite.
