Support iPadOS (iPad) & iOS (iPhone) apps in non-`get`/`install`/`update` commands

Overview

Support iPadOS (iPad) & iOS (iPhone) apps in non-get/install/update commands:

When app IDs are (or --all is) supplied to a non-get/install/update command, the command should process each app ID regardless of the app's platform.

Commands

All commands that output apps should include a platform field in tabular & JSON output that indicates the platform of the app: macOS, iOS, iPadOS, Mac Catalyst, or anything else.

The following commands should process all apps regardless of platform:

• home
• list
• lookup/info
• open
• outdated (--accurate is macOS-only)
• search
• seller/vendor
• uninstall

--platforms

Maybe add support for a --platforms option for when a command is run without app IDs:

platforms_option ::= "--platforms" <platform> [ "," <platform> ]…`
platform ::= "macos" | "ios" | "ipados" | "all"

<platform> would probably be case insensitive.

--platforms would default to all (or maybe macos).