add more controllers and fix tests

app/Http/Requests/PurchaseOrders/PurchaseOrderIndexRequest.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Http\Requests\PurchaseOrders;
+
+use App\Http\Requests\ApiFormRequest;
+
+class PurchaseOrderIndexRequest extends ApiFormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'q' => ['nullable', 'string', 'max:100'],
+        ];
+    }
+}