Add audit log entry when CI/CD settings are accessed

What does this MR do?

MVC on #8073 to unblock https://gitlab.com/gitlab-com/access-requests/issues/1266#note_257640154. Whenever someone accesses CI/CD settings page of a project/group, add an audit log entry.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content