Is your feature request related to a problem? Please describe.
The string download_sure ("Are you sure you want to download") is not currently used in the code (why does it even exist?), but if it were, it would probably be implemented like this: It would concatenate the string with the URL in code (string + " " + url + "?"). This makes translations awkward, as translators cannot position the URL naturally in other languages.

Describe the solution you'd like
Use a placeholder for the URL in the string itself, for example:

Are you sure you want to download %(url)?

In German, we could simply write something like this with the placeholder approach:

Möchtest du wirklich %(url) herunterladen?

Additional context
This affects all languages where sentence structure differs from English. In some, the URL is not put at the end of the sentence.