Adding SSL check for clients

SSL for Clients

The scenario that sparked this change is based around the nginx setting to force client two-way authentication. A big part of this can be found in the second merge request linked to this one, where we prepare the Dockerfile that is used to create the GitLab test image.

What we do here is, we create a gitlab instance where we activate SSL and use HTTPS as well as activate the nginx two-way authentication option and setting the authority certificate as baseline.

This is the counterpart to https://gitlab.com/gitlab-org/gitlab/-/merge_requests/54060