display destination file before youtube-dl download

display destination file before youtube-dl download

Rather than after it, which can leave one wondering what file it's
downloading.

youtubeDl should not ever return Right Nothing in normal operation,
becaause it's already asked youtube-dl if it supports the url. So it
would have to succeed at that, then not download any file, but also
exit successfully, in order for the new error message to display.

Also display the name of yt-dlp when using it.