Return the bare signature from the MAYO, SNOVA, QR-UOV, SQIsign and AIMer signers rather than the NIST crypto_sign signed-message envelope, and require verification to be given exactly the parameter set's signature length, so that a signature no longer carries a copy of the signed data into every certificate and CMS structure built on it and trailing bytes are no longer ignored, with the KAT tests rebuilding the envelope as FalconTest already does, relates to github #2403.