t_client.sh: Allow to skip tests

t_client.sh: Allow to skip tests

Individual tests can define a script to run to test
whether they should be skipped.

Included in this commit is an example check which
checks whether we can do NTLM checks. This fails
e.g. on recent versions of Fedora with mbedTLS
(tested with Fedora 39) or when NTLM support is not
compiled in.

v2:
 - ntlm_support:
   - support OpenSSL 3
   - allow to build without cmocka
v3:
 - add example to t_client.rc-sample
 - t_client.sh code style
 - use syshead.h in error.h
v5:
 - rename SKIP_x to CHECK_SKIP_x

Change-Id: I13ea6752c8d102eabcc579e391828c05d5322899
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20240308102818.9249-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/search?l=mid&q=20240308102818.9249-1-gert@greenie.muc.de
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 0c7cf0694ee6f878168330e9a084c255c51a9e8b)