gpgsm: add a certificate chain check for de-vs compliance

* sm/certchain.c (do_validate_chain): fix typo
* sm/decrypt.c (gpgsm_decrypt): check the certifacte chain for de-vs
compliance
*sm/verify.c (gpgsm_verify): check the certificate chain for de-vs
compliance

The gpgsm status for CO_DE_VS compliance should only be set if the
certificate chain is also checked and compliant (besides the pk algo,
the message digest and cipher which were already checked before).

• GnuPG-bug-id: T8188