#shell to powershell

The original shell version is here: https://derflounder.wordpress.com/2023/06/30/listing-and-downloading-available-macos-installers-using-apples-softwareupdate-tool/#more-12084. The basics are simple: use the sofwareupdate command to display a list of available updates for a given Mac and let the user pick the one they want to download. This doesn’t install it, just downloads them. Because I…