Add support for /info API endpoint that returns metadata about search results

[jmiranda]

We will also need a new backend URL API functionality called "info". The new urls for the API should be (see image below):

The "info" method (/info url) is sent to the backend with search criteria. And the backend returns the information about the last entry modification date and the total number of entries for that entry criteria, no need for pagination. See below an screenshot example of Request Headers, Query String parameters and Response headers on an /info url request.

And the server response would be (see image below):