Remove N+1 queries for projects search
From https://gitlab.com/gitlab-org/gitlab/blob/master/ee%2Fspec%2Ffeatures%2Fsearch%2Felastic%2Fglobal_search_spec.rb#L47 we can see there is a 4N+1 query for loading projects in search.
This is quite inefficient and probably at least some of these can be preloaded.