Fix n+1 in search show page

[sonalkr132]

This won't have any noticeable effect on /api/v1/search. In api search it would only make one fewer sql query per record because gem_download for gem.latest_version is now eager loaded.

On search show page this makes 60 fewer calls to database(2 per record).

with_versions is expendable because the search condition already uses versions.indexed in its condition.

[sonalkr132]

Even after this patch search api would be making 4 db calls for each rubygem. It is mostly because rubygems payload is huge(there are 30 such rubygems in single response). It is too expensive to expose that many attributes. I think I will fix this with AMS.