content views - filters - ui - add ability to create/view/delete rules

This is an initial commit to add content view definition filters rules in
to the UI.  This allows the user to create a rule for a filter, view
it in the list of rules and delete.

It does not support editing the rule or adding more details (e.g.
pkgs/groups/errata, include/exclude...etc).  Those changes will
come in a separate commit.