TT#126809 Add extra pager elements to have better visibility on AUI in iframe

The in field testing showed the following pager numbers for the best usability:

FullHD:
  * v1/iframe: 15 elements per page is the best
  * v2:        18 elements per page (will be 20 after removal "GO TO OLD ADMIN PANEL" banner)
2K:
  * v1/iframe: 20 elements per page
  * v2:        25 elements per page
4K:
  * v1/iframe: 35 is the best
  * v2:        50 elements per page (45 actually, but 35/50 can be used for now).

Change-Id: Ibcc0c9bd663d477151ea3449cb2e82e8276ec079
(cherry picked from commit d3a7825df1)

share/templates/helpers/datatables.tt

@@ -77,7 +77,7 @@ $(document).ready(function() {
         "sPaginationType": "bootstrap",
         [% IF helper.length_change %]
             "bLengthChange": true,
-            "aLengthMenu":  [% helper.length_menu || '[[ 5, 10, 50, 100, 250, -1], [5, 10, 50, 100, 250, "All"]]' %],
+            "aLengthMenu":  [% helper.length_menu || '[[ 5, 10, 15, 20, 35, 50, 100, 250, -1], [5, 10, 15, 20, 35, 50, 100, 250, "All"]]' %],
         [% ELSE %]
             "bLengthChange": false,
         [% END %]