REGTESTS: ssl: test ssl_c_used, ssl_c_san and ssl_c_ca_err_depth

REGTESTS: ssl: test ssl_c_used, ssl_c_san and ssl_c_ca_err_depth

These three client certificate fetches were the ones the ssl_c_* test
did not report, the first two only because they were forgotten, the
last one because it needs a chain which does not verify.

The first client gets the two easy ones plus ssl_c_err and ssl_c_ca_err
which must both be zero for the certificate which does verify.

A second listener sends common.pem as a client certificate. It carries
a subjectAltName, which client1.pem does not, and its intermediate CA
is unknown to the ca-file of the bind line, so the chain breaks at
depth 1 and ssl_c_ca_err_depth reports it. Being a server certificate,
it also fails the purpose check at depth 0, hence the "ca-ignore-err
all" added next to the existing "crt-ignore-err all" so that the
handshake completes and the fetches can be read.