fixes #5026 / BZ 1094176 - content view package group filter - handle duplicate group names across repos

The current logic for package group filters does not properly handle the
case where a content view has multiple repositories with the same or overlapping
package groups (e.g. 2 repos w/ package group named X).  The issue is that
the package group selection is based upon name; however, it needs to be more
specific than that.

This commit updates the package group filtering to not identify the group
by name, but instead by the pulp id/uuid for the group.  This way when
a user selects a group, they are choosing a specific one from a specific
product/repo.

The following are high-level changes introduced with this commit:
1. add uuid to the content_view_package_group_filter_rule
2. update the API and UI to show the product and repo name that
   each package group is associated with
3. update API and UI to behave correctly when a user adds/removes
   package groups from a filter
4. update the publishing logic to utilize the package group uuid
   when applying the filter
fixes #6197 - moving host/guests to virtual_host/virtual_guests

This corrects conflict with foreman host link

rubocop fix

spec test fix
Fixes #6242 - remove unused distributor from rabl to fix error.

There was an HTTP 500 on subscription show if you were not admin
(or didn't have the distributor read permission) because distributor
was still referenced from the rabl.  This commit removes the reference.
Merge pull request #4275 from waldenraines/6242

Fixes #6242 - remove unused distributor from rabl to fix error.
fixes #6215 - do not pass full objects to rabl

fixes #6215 - return available_content to products node

fixed test
Merge pull request #4248 from bbuckingham/issue-5026

fixes #5026 / BZ 1094176 - content view package group filter - handle duplicate group names across repos
Merge pull request #4264 from thomasmckay/6197-host-guest

6197-host-guest - moving host/guests to virtual_host/virtual_guests
Merge pull request #4266 from thomasmckay/6215

fixes #6215 - do not pass full objects to rabl