Port ssl_cert_errors meta data from KSslError to QSslError

Summary:
The TCPSlaveBase side of this can be fully ported to QSslError once D24928
is in.

Reviewers: nicolasfella

Reviewed By: nicolasfella

Subscribers: ahmadsamir, nicolasfella, kde-frameworks-devel

Tags: Frameworks

Maniphest Tasks: T11620

Differential Revision: https://phabricator.kde.org/D24980