Add ability to download Xcode without logging in using XcodeRelease

[MattKiazyk]

I hate having to log into my Apple Developer account, always having to put in my 2fa code, when I want to download Xcode, but Apple has never given us the ability to do so.

As a CI user, it sucks that I have to type in my credentials all the time, while trying to do a xcode install on multiple machines.

This PR changes that.

By using a public URL provided by Apple, we can get a token cookie that can be used to download the version of Xcode that we wish, without having to provide a log in. 🎉

Caveats:

• This does not work when using the Apple datasource. More specifically that token doesn't work for listing the Xcode versions with https://developer.apple.com/services-account/QH65B2/downloadws/listDownloads.action

[ghost]

@MattKiazyk Does it still work? CLI asks me for Apple ID and if I do the ADCDownloadAuthCookie trick manually with curl it redirects me to:

Location: https://developer.apple.com/unauthorized/