Allow SmartCard authentication to use SAN extensions

What does this MR do?

This adds flexibility to the SmartCard authentication with X.509 certificates by using SubjectAlternateName (SAN) extensions to pickup the email address (rfc822Name) that match as an alternate name for the GitLab instance (URI), which removes the limitation of using the email as part of the Common-Name of the certificate.

Related links

Issue: https://gitlab.com/gitlab-org/gitlab-ee/issues/8605

CE backport: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/32581

Omnibus MR: omnibus-gitlab!3566 (merged)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #8605 (closed)