Add GK (Graykey) checkbox to auto download extraction upon completion

In Graykey Just like how there is a check box to automatically start bruteforce after an extraction is completed, there should be a checkbox to automatically download the extraction when it is completed. I do not want to download the extraction while the extraction takes place, as I've found it's slower than waiting it to finish and just starting the download, and I've had failures where I had to re-do the extraction. This checkbox should be configurable in settings to automatically be checked or unchecked, with the user being able to override it on each extraction done.