Support for admin to update order item quantity

+  /**
+   * {@inheritdoc}
+   */
+  public function extractFormValues(FieldItemListInterface $items, array $form, FormStateInterface $form_state) {
[...]
+      $order_item->setQuantity($values['value']);
+      $unit_price = $this->chainPriceResolver->resolve($purchased_entity, $order_item->getQuantity(), $context);
+      $order_item->setUnitPrice($unit_price);
+    }
+  }
+

It doesn't feel right for the widget to do this. Shouldn't commerce handle this by refreshing the order?

What about adjustments and other things that come from order processors - do they run after these changes are made? I'm pretty sure they would need to.

Re-rolling.