List view for grouped search results - A - Update the result count message

[mejackreed]

Split out of #681

A: Update the result count message. Since the user is interested in seeing results via collections, the message should reflect the number of collections returned by the query, instead of documents (the number of docs per collection is covered in F). Showing 10 collections per page, each with several docs, does seem like it will create a large page (vertically and page-load wise), but we have the per-page dropdown to consider, and we're not sure how easily we can operate with two per page approaches in the same app.

• Display a result count message in the format "1 - x of y collections" where x uses the per-page parameter (based on the number of groups/collections) and y is the total number of groups/collections returned by the grouped query.