fixes #8491 - removing puppet modules list from content view version api

This takes the CVV index api from ~5 minutes down to 17 seconds
for 47 content view versions, 10 having 100 puppet modules, the rest having
5
Why not just extend https://github.com/Katello/katello/blob/master/app/views/katello/api/v2/common/_metadata.json.rabl ?