Fixed streamed outputs in more extreme scenarios

Fixes hitting memory limits where downloaded file sizes are much greater
than memory limit. Stopping and flushing output buffer seemed to stop
limits causing issues when fpassthru is used.
Tested with 24M memory limit and 734M file

app/Http/Controllers/Controller.php

@@ -127,6 +127,7 @@ abstract class Controller extends BaseController
     protected function streamedDownloadResponse($stream, string $fileName): StreamedResponse
     {
         return response()->stream(function() use ($stream) {
+            ob_end_clean();
             fpassthru($stream);
             fclose($stream);
         }, 200, [