Expect Alexanders API to fail or be slow sometimes

Problem/Motivation

The commerce_alexanders module creates API requests and if it is broken for whatever reason that's it. There is no retry or anything. See \commerce_alexanders_commerce_order_update(). It does:

    $alexanders_order = AlexandersOrder::create([
      'order_number' => $order->id(),
      'rush' => $order->hasField('alxdr_rush') && $order->get('alxdr_rush')->value,
      'standardPrintItems' => $alexanders_order_items,
      'shipping' => $alexanders_shipment,
    ]);
    $alexanders_order->save();
    $api = new AlexandersApi();
    $api->createOrder($alexanders_order);

And createOrder() does

    $orderData = $this->buildOrderData($order);
    $url = $this->generateUrl()->toString();
    try {
      $response = $this->client->post($url, $orderData);
    }
    catch (RequestException $e) {
      watchdog_exception('alexanders', $e);
      return FALSE;
    }
    return $this->processResponse($response);

So the good news is that we've logged the fail but there's no retry. Also if the Alexanders API starts to timeout this will make order updates vulnerable to PHP timeouts.

Proposed resolution

In general it is best to queue such API requests rather do them inline. Discuss the best solution.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet