Added usage check to delete endpoints

app/Exceptions/Api/EntityStillInUseApiException.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Exceptions\Api;
+
+class EntityStillInUseApiException extends ApiException
+{
+    private string $modelToDelete;
+
+    private string $modelInUse;
+
+    public function __construct(string $modelToDelete, string $modelInUse)
+    {
+        parent::__construct('', 0, null);
+        $this->modelToDelete = $modelToDelete;
+        $this->modelInUse = $modelInUse;
+    }
+
+    public const string KEY = 'entity_still_in_use';
+
+    /**
+     * Get the translated message for the exception.
+     */
+    #[\Override]
+    public function getTranslatedMessage(): string
+    {
+        return __('exceptions.api.'.$this->getKey(), [
+            'modelToDelete' => __('validation.entities.'.$this->modelToDelete),
+            'modelInUse' => __('validation.entities.'.$this->modelInUse),
+        ]);
+    }
+}