feat: refactor featured variants to group items, including new controller and resource implementations

app/Domains/Catalog/Resources/GroupItemResource.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Domains\Catalog\Resources;
+
+use App\Domains\Bundle\Models\Bundle;
+use App\Domains\Catalog\Models\ProductVariant;
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class GroupItemResource extends JsonResource
+{
+    public function toArray(Request $request): array
+    {
+        return [
+            'id' => $this->id,
+            'featured_group_id' => $this->featured_group_id,
+            'groupable_type' => match ($this->groupable_type) {
+                ProductVariant::class => 'variant',
+                Bundle::class => 'bundle',
+                default => 'unknown',
+            },
+            'groupable_id' => $this->groupable_id,
+            'order' => $this->order,
+        ];
+    }
+}