fix: prevent null metadata

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Service/File/FileListService.php

@@ -135,7 +135,7 @@ private function formatSingleFileData(
 			'uuid' => $fileEntity->getUuid(),
 			'name' => $fileEntity->getName(),
 			'status' => $fileEntity->getStatus(),
-			'metadata' => $fileEntity->getMetadata(),
+			'metadata' => $fileEntity->getMetadata() ?? [],
 			'createdAt' => $fileEntity->getCreatedAt(),
 			'userId' => $fileEntity->getUserId(),
 			'signatureFlow' => $fileEntity->getSignatureFlow(),