List: prevent extra scrolling on keypress events on "Select All" checkbox (#31602)

Author: dmirgaev

packages/devextreme/js/__internal/ui/list/list.edit.decorator.selection.ts

@@ -226,6 +226,7 @@ class EditDecoratorSelection extends EditDecorator {
 
   _selectAllHandler(event: DxEvent<KeyboardEvent>): DeferredObj<unknown> {
     event.stopPropagation();
+    event.preventDefault(); // to prevent scrolling on space key press
     this._list._saveSelectionChangeEvent(event);
 
     const { value } = this._selectAllCheckBox?.option() ?? {};

packages/devextreme/js/__internal/ui/list/list.edit.ts

@@ -80,6 +80,8 @@ class ListEdit extends ListBase {
           } else {
             parent.downArrow(e);
           }
+        } else {
+          e.preventDefault(); // to prevent extra scrolling
         }
       }
     };