Add questions to Service Desk's KB search results

Currently you can search a KB (a Confluence space) from the Service Desk home screen before you create a request, it would be great to have CQ questions show up in the results there as well.

I had a chat to Gil, who said they can modify their existing UI to also search on a set of labels, but they'd need us to modify the Confluence capabilities API to include information about whether or not CQ is installed.

Once we've added that they can modify their search.