Add CRL support to X.509 verification

Hello!

I've been working on updating some code to utilize cryptography in favor of PyOpenSSL due to the API deprecation in the older project.

The only code that I can not currently remove is related to the use of X509Store and X509StoreContext. That is utilized for doing certificate validation. For example:

    def verifyACertificate(self, cert: c_x509.Certificate):
    	'''
    	Check if a Certificate is trusted by a set of CAs and is not revoked.
    	'''
        crls = self.getCaCrls()  # type: List[c_x509.CertificateRevocationList]
        cacerts = self.getCaCerts()  # type: List[c_x509.Certificate]

        store = crypto.X509Store()  # This is pyopenssl...
        [store.add_cert(crypto.X509.from_cryptography(cacert)) for cacert in cacerts]

        if crls:
            # Setting flags is important. Other uses use things such as PARTIAL_CHAIN flags.
            store.set_flags(crypto.X509StoreFlags.CRL_CHECK | crypto.X509StoreFlags.CRL_CHECK_ALL)
            [store.add_crl(crypto.CRL.from_cryptography(crl)) for crl in crls]

        ctx = crypto.X509StoreContext(store, crypto.X509.from_cryptography(cert))
        try:
            ctx.verify_certificate()  # raises X509StoreContextError if unable to verify
        except crypto.X509StoreContextError as e:
            mesg = _unpackContextError(e)  # helper function to unpack the X509StoreContextError, not important here.  
            raise Exception(mesg)
        return cert

I believe my use case aligns with https://github.com/pyca/cryptography/issues/10276 ( doing code signing and/or user cert verification ). Current docs for the verification APIS ( https://cryptography.io/en/42.0.2/x509/verification/ ) don't seem to support setting CRLs or flag setting.

Is this type of use case in scope for work in https://github.com/pyca/cryptography/pull/10345 ?

Start with the X.509 verification API documentation linked in the issue and PR #10345, then compare its current scope with the shown PyOpenSSL X509Store/X509StoreContext flow. Done means there is a decided path for CRL-aware certificate verification and flag configuration for code-signing or user-certificate verification; the issue names no implementation files or tests.