update kirby to v5 and add refresh cache panel view button

public/kirby/src/Cms/FilePermissions.php

@@ -13,7 +13,15 @@ namespace Kirby\Cms;
  */
 class FilePermissions extends ModelPermissions
 {
-	protected string $category = 'files';
+	protected const CATEGORY = 'files';
+
+	/**
+	 * Used to cache once determined permissions in memory
+	 */
+	protected static function cacheKey(ModelWithContent|Language $model): string
+	{
+		return $model->template() ?? '__none__';
+	}
 
 	protected function canChangeTemplate(): bool
 	{