Add commands to interact with the Apple Account of the current macOS user

Possibly add new commands / modify existing commands to better interact with the Apple Account of the current macOS user (e.g., add --macos & --app-store options or add new commands).

account, signin, signout & some other commands work with the Apple Account in the Mac App Store, which is a separate setting from the Apple Account of the current macOS user.

Normally, the two are set to the same account, but they could be set to different accounts.

Disambiguate what accounts each command works with.

macOS user Apple Account

The macOS user Apple Account is associated with the current macOS user in System Settings/System Preferences. It can be observed:

• In Swift:

(UserDefaults.standard.persistentDomain(forName: "MobileMeAccounts")?["Accounts"] as? [[String: Any]])?.first?["AccountID"]

• From command line:

defaults read MobileMeAccounts | plutil -extract "Accounts".0."AccountID" raw -o - -

Mac App Store Apple Account

The Mac App Store Apple Account, which is when you login in the App Store app. It can be observed:

• In Swift (in macOs <= 10.12.x):

ISStoreAccount.primaryAccount.identifier

• From command line: not sure

Commands

Currently, I think that the commands, when working, have the following interactions with the macOS & MAS Apple Accounts:

• MAS
  • account
  • signin
  • signout
• MAS (requires app in installed app list)
  • update
• MAS (requires app not in installed app list)
  • get
  • install
  • lucky
• Neither
  • help
  • home
  • list
  • lookup
  • open
  • outdated
  • reset
  • search
  • seller
  • uninstall
  • version

Start by reviewing the existing implementations of account, signin, signout, update, get, install, and lucky, then compare them with the MobileMeAccounts and Mac App Store account APIs described in the issue. The work is done when the commands clearly distinguish which Apple Account they use and the chosen command or options consistently interact with the intended account.