Fixes #4964, #4963: Product json incorrectly grabbed all repositories.

The products rabl view switched the order of the node name and the
scope to grab the data. Instead of calling 'library_repositories' and
setting that equal to a 'repository' node in the JSON output, the view
was getting all repositories and placing them at a library_repositories
node. The consequences of this were that attempting to fetch a product
list while a content view publish is occurring means that repositories
outside the default content view are attempted to have their sync status
checked before they ever exist in Pulp.