As system, I should be able to export testruns data paginated whenever using the REST API

As system, I should be able to export the testruns paginated whenever using the REST API.

Therefore, the endpoint  "GET /rest/raven/1.0/testruns" (see here) should be evolved to support additional parameters:

• limit: Integer, max amount of Test Runs per paginated data (default: 10)
• page: Integer, page of paginated data (default: 1)

We will also add a setting in configuration page defining "Max results per request". If any request, paginated or not returns more than this list of elements, an exception must appear.