In LS 2 I patched file upload in order to permit download of files. For obtaining this feature I edited modaldialog.js. It works.
Now I need to do this in LS 4.5.

I found that file to be edited is application/views/survey/questions/answer/file_upload/answer.twig.

I have two questions:
1) I need further variables in order to reconstruct the download url:
https://qsnap-ls.comune.napoli.it/upload/surveys/$surveyid/files/$filename
How can I import them in .twig file.
2) for avoiding to modify a distribution file, is there a way to do this in some question theme file? I didn't find documentation about question theming.