[UX] selection choices for content host subscriptions
On the "Add" subscriptions page for content hosts, there needs to be a multi-choice selector to filter the subscriptions listed. The choices correspond to the params in subscriptions_controller.rb#index
match_host : "Match content host"
match_installed : "Match installed products"
no_overlap : "Match products not already covered"
Toggling one of these choices should result in that parameter being included in the next search.