feat: fallback to OOT scheme

[szymonrybczak]

Summary:

When building app for macOS a scheme looks like this AppName-macOS. Inside run-macos implemention in react-native-macos repo it's hardcoded assumption. I think we can also support this, so if the default one is not accessible, let's give a warning and fallback to one with the suffix.

Test Plan:

1. Clone the repository and do all the required steps from the Contributing guide
2. Follow steps described here to add OOT platform e.g. inside react-native-macos
3. Run this command inside app that is using OOT platform:

node /path/to/react-native-cli/packages/cli/build/bin.js run-macos

4. Fallback scheme should be selected, so in this case ProjectName-macOS

Checklist

• Documentation is up to date to reflect these changes.
• Follows commit message convention described in CONTRIBUTING.md