Selenide cannot download files with cyrillic (and probably any UTF-8) name

[asolntsev]

The problem

Given a file with cyrillic letters, Selenide downloads it, but with a wrong name.

Details

1. Call method File file = $("a").download();
2. The downloaded file should contain cyrilic letters (like файл-с-русским-названием.txt)
3. But Selenide creates a file with a wrong name in which all cyrillic letters are replaced with spaces (like - - - .txt)

[rosolko]

Closed via #689