Take the example of the following issue http://projects.theforeman.org/issues/6807
1. create a host collection
2. add two new hosts to host-collection
3. Go to the host collections index page. 
Notice that the content hosts count has not been updated

Similar bugs occur on
* Product/Repositories page (where we add a repo to the product and the index still shows the previous number) 
* Content Views, where the repo/env names are not similartly update
* Gpg Keys with the product/repo count 
and so on. This is probably true for every nutupane page.

We need a generic mechanism/service to automatically update the Index list when we change specific details of one of the items