Return an array for listed_records accessor of list-form

Closes #13094
(grafted from d297c252aa7b0c483de0695ee945f672af67ce3f)

--HG--
branch : 7.0

sao/src/view/list_form.js

@@ -111,7 +111,7 @@
             return records;
         },
         get listed_records() {
-            this.group.slice();
+            return this.group.slice();
         },
         set_cursor: function(new_, reset_view) {
             if (new_) {