[Feat]: Enable support for multiscreen

[ovidiubarbu]

Is your feature request related to a problem? Please describe.
I have an Android device with output on 2 displays. Right now, I can see the display 0 ( which seems to be the default), but could not find a way to see display 1 in Appium Inspector, or to access its UI elements. Infotainment systems have multiple displays and would be very helpful to be able to automate UI on more than 1 screen.

Describe the solution you'd like
Support added to be able to point to the display needed, and be able to see it in the Inspector and access it's elements programmatically. ( seems like ADB could be used to take screenshots/xml_dump on a different screen, and Android Studio also has support for it )

Describe alternatives you've considered
Could not find any alternative at the moment.

Additional context
I had a discussion about this here, if it would help while developing:
appium/appium#19639

Thank you for considering this.