Add count of all items in Common Data Service entity to the UI.

[Redbeard]

I would like to see the ability to count all the items in a Common Data Service entity in the CDS UI screen.  Currently it pages all of the results to it's difficult to determin how many records are there.

[ChrisKoenig]

It would also be helpful to be able to tell the number of rows for a specific query, and from "Get List" as well