Add back CLI --platform option

[tokou]

Proposed changes

• I saw that the --platform option existed in the past and has been deprecated in 1.11.0
• I was wondering of the reason behind it as I think it might be very useful in local development scenarios
  • I often have one iOS and one Android device running as I develop a new feature
  • We often write single flows that run on both platforms
  • I'm often working on fixing code for a flow on a single platform at a time (generally Android then iOS)
  • I find myself having to always select a device while using --platform would make things much simpler for me
• The way I suggest adding it back here is in an optional fashion
  • No --platform works as before
  • --platform gets ignored in case --device is set
  • --platform set and a single device from that platform is connected: We select that device without prompt
  • --platform and multiple devices from that platform are connected: We prompt the user with only the relevant platform devices displayed
• If there's an issue with reverting it at the App level that I did not notice. May I suggest adding it to the TestCommand only in that case?

Testing

• Run --platform alongside --device
• Run --platform with a single device from each platform running
• Run --platform with multiple devices from different platforms running

Issues fixed

Linked #314

[tokou]

I'm more and more thinking that this should be added to the Test command only 🤔 wdyt @bartekpacia ?

[bartekpacia]

There's also maestro hierarchy command which should also work with --udid and --platform options.

But overall yes, I agree that --platform (and --udid) shouldn't be top-level options on the maestro command. But to keep consistency, let's continue doing it.

In a separate PR you might want do add those options to individual commands (and deprecate those top-level options, so we can remove them later).