feat: add rate limits on the TLS connection level

What does this MR do?

See https://gitlab.com/gitlab-org/gitlab-pages/-/issues/632

The whole idea is just to hook into the GetCertificate function and return an error if the rate limit is reached. Everything else is making this work. =)

TODO

• I added the Changelog trailer (e.g. Changelog: added) to the commits that need to be included in the changelog
• I added unit tests or they are not required
• I added acceptance tests or they are not required
• I added documentation (or it's not required)
• I followed code review guidelines
• I followed Go Style guidelines