Ahmad Samir authored Aug 20, 2020 and Elvis Angelaccio committed Aug 26, 2020

- No need to stat the url we get from QFileDialog::getSaveFileUrl, if it
  already exists the dialog should show the "do you want to overwrite?"
  message to the user on its own; also no need to check for isValid, the
  dialog will return valid urls, AFAICS
- KIO::file_copy will check if the src url exists ...etc, we don't have
  to do that manually; also make the job async, and re-use the custom error
  messages where possible