Fixes #5532: Wraps content search in Foreman permission system.

Basic ideas of how content search is wrapped in permissions:

If you have :view_products and :view_lifecycle_environments on Library
you can see all the products, repositories, errata, puppet modules and
packages that you have view access on.

If you have :view_content_views and :view_lifecycle_environments you
can see all the content views and subsequent products, repositories,
errata, puppet modules and packages that you have view access on in the
environments that you have view access on. This does not include the
default content view. See the previous comment on how to see the default
content view.