Replace scrollbars in sidemenu

jet/static/jet/css/_sidebar.scss

@@ -8,8 +8,9 @@
     margin-bottom: 32px !important;
 
     &-wrapper {
-      overflow-y: auto;
+      overflow: hidden;
       height: 100%;
+      position: relative;
     }
 
     &-item {

jet/static/jet/js/main.js

@@ -864,6 +864,10 @@
             }
         };
 
+        var initScrollbars = function() {
+            $('.sidebar-menu-wrapper').perfectScrollbar();
+        };
+
         initjQueryCaseInsensitiveSelector();
         initjQuerySlideFadeToggle();
         initFilters();
@@ -878,5 +882,6 @@
         initTooltips();
         initDashboard();
         initUnsavedChangesWarning();
+        initScrollbars();
     });
 })(jet.jQuery);