Force dateFormat to dd/mm/yyyy for all locales

To maintain consistency and the use of advanced search in the frontend,
we forced the expected date format for all languages. This is a temporary
solution that we should analyze in depth to allow different date formats
depending on the language in the filters.

app/assets/javascripts/advanced_search.js

@@ -25,6 +25,7 @@
       });
       $(".js-calendar-full").datepicker();
       $.datepicker.setDefaults($.datepicker.regional[locale]);
+      $.datepicker.setDefaults({ dateFormat: "dd/mm/yy" });
     },
     initialize: function() {
       App.AdvancedSearch.init_calendar();