Add pagination

[rnowling]

Instead of returning all parameter sets, models, and tests, allow sorting and paging. Example page structure:

{
    "pagination": {
                "_links": {"next": {"href": "/v2/animals?type=dog&page=2"}},
                "count_per_page": 20,
                "current_page": 1,
                "total_count": 146386,
                "total_pages": 7320
    }
}