select options for products + skus, photos form

templates/ProductSkus/select.php

@@ -0,0 +1,13 @@
+<?php
+/**
+ * @var \App\View\AppView $this
+ * @var iterable<\Cake\Datasource\EntityInterface> $productSkus
+ */
+
+$this->setLayout('ajax');
+
+?>
+    <option value="">Select a SKU</option>
+<?php foreach ($productSkus as $productSkuId => $productSku): ?>
+    <option value="<?= $productSkuId; ?>" <?= $this->request->getQuery('product_sku_id') == $productSkuId ? 'selected="selected"' : ''; ?>><?= $productSku; ?></option>
+<?php endforeach; ?>