Make repo settings code intelligence page enterprise-only
Created by: efritz
This hides the CodeIntelligence page in repo settings when running in OSS mode. This follows the same strategy that is used to display or hide components in the site-admin page.
This was greater effort as this is the first repo settings page that is not available in OSS.
The consequence of not having this change in 3.10 is a navigable link to a page that immediately throws an error because the GraphQL backend is not supported in non-enterprise installations.