title: Override KNP Paginator entity
body: <p>I am currently working with KNP Paginator to paginate results. 
  I get serialize paginator object and get response in following form:</p>
  
  <pre><code>  "current_page_number": 1
    "num_items_per_page": 5
    "items": [5]
    "total_count": 35
    "paginator_options": {
    "pageParameterName": "page"
    "sortFieldParameterName": "sort"
    "sortDirectionParameterName": "direction"
    "filterFieldParameterName": "filterField"
    "filterValueParameterName": "filterValue"
    "distinct": true
    }-
    "custom_parameters": [0]
    "route": "api_tags_list"
    "params": [0]
    "page_range": 5
    "template": "KnpPaginatorBundle:Pagination:sliding.html.twig"
    "sortable_template": 
    "KnpPaginatorBundle:Pagination:sortable_link.html.twig"
    "filtration_template": 
    "KnpPaginatorBundle:Pagination:filtration.html.twig" 
  </code></pre>
  
  <p>Is it possible to override KNP paginator entity so that response will not include <code>templates</code> but included <code>total number of pages</code>? </p>
  
  <p>Desired output:</p>
  
  <pre><code>  "current_page_number": 1
    "num_items_per_page": 5
    "items": [5]
    "total_count": 35
    "paginator_options": {
    "pageParameterName": "page"
    "sortFieldParameterName": "sort"
    "sortDirectionParameterName": "direction"
    "filterFieldParameterName": "filterField"
    "filterValueParameterName": "filterValue"
    "distinct": true
    }-
    "custom_parameters": [0]
    "route": "api_tags_list"
    "params": [0]
    "page_range": 5
    "total_page_number": 7
  </code></pre>