Fixes #5111 - CSV handles collection or container

There was an issue where collections and containers in the csv adapter
was returning just ruby hashes. This fixes the issue by expanding out
the columns.
Special thanks to @komidore64 and @tstrachota!

Container output:

     label _("GPG") do
       from :gpg_key do
         field :id, _("GPG Key ID")
         field :name, _("GPG Key")
       end
     end

Headers would be GPG::GPG Key ID, GPG::GPG KEY

Collection output:
    collection :productContent, _("Content") do
      from :content do
        field :name, _("Repo Name")
        field :contentUrl, _("URL")
      end
     end

Headers would be Content::name::1, Content::URL::1, Content::name::2,
Content::name::3, etc.. depending on how many :productCotents there are.
Merge pull request #112 from dustint-rh/csv_container_fields

Fixes #5111 - CSV handles collection or container