[DURACOM-253] Fix scrollbar issue on Firefox on Windows

Author: davide-negretti

src/app/admin/admin-sidebar/admin-sidebar.component.scss

@@ -138,3 +138,9 @@
     }
   }
 }
+
+::ng-deep {
+  .browser-firefox-windows {
+    --ds-dark-scrollbar-width: 20px;
+  }
+}