change super_group to grouped_options

Author: engcom-Charlie

app/code/Magento/GroupedProduct/Model/Product/Type/Grouped.php

@@ -415,7 +415,7 @@ protected function _prepareProduct(\Magento\Framework\DataObject $buyRequest, $p
                 );
                 if ($buyRequest->getSuperGroup()) {
                     $serializedValue = $this->serializer->serialize($buyRequest->getSuperGroup());
-                    $_result[0]->addCustomOption('super_group', $serializedValue);
+                    $_result[0]->addCustomOption('grouped_options', $serializedValue);
                 }
 
                 $products[] = $_result[0];

app/code/Magento/GroupedProduct/Model/Quote/Item/CartItemProcessor.php

@@ -109,11 +109,11 @@ public function processOptions(CartItemInterface $cartItem): CartItemInterface
             return $cartItem;
         }
 
-        $superGroup = $cartItem->getOptionByCode(self::SUPER_GROUP_CODE);
-        $superGroupValues = $superGroup ? $this->jsonSerializer->unserialize($superGroup->getValue()) : null;
-        if ($superGroupValues) {
+        $groupedOptions = $cartItem->getOptionByCode('grouped_options');
+        $groupedOptionsData = $groupedOptions ? $this->jsonSerializer->unserialize($groupedOptions->getValue()) : null;
+        if ($groupedOptionsData) {
             $productOptions = [];
-            foreach ($superGroupValues as $id => $qty) {
+            foreach ($groupedOptionsData as $id => $qty) {
                 $productOptions[] = $this->groupedOptionFactory->create(['id' => $id, 'qty' => $qty]);
             }