Hide admin Audit Log in sidebar when not licensed

What does this MR do?

Admin Audit Log is a EEP feature, so when the license does not allow that feature, we should hide the button from the sidebar.

Why was this MR needed?

Clicking the button resulted in a 404.

In the old nav, the button was already shown conditionally.

Does this MR meet the acceptance criteria?

• [-] Changelog entry added, if necessary
• [-] Documentation created/updated
• [-] API support added
• Tests
  • [-] Added for this feature/bug
  • [-] All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes gitlab-org/gitlab-ee#3197.