[FEATURE] TNS command for screen recording on-device

Hey Nativescript team,

As always thanks for all the hard work -- using Nativescript Vue and enjoying it immensely!

After being thoroughly impressed by the tns resources splashes generate command, I thought it would be great to have a tns subcommand that started/stopped/extracted screen recordings from a device. It's not hard to do with recent versions of android (adb shell screenrecording /sdcard/whatever.mp4), but it might be even more convenient to use a tns command to do it (and pull out the file afterwards).

(I hope I'm filing this feature request properly -- none of the template instructions seemed to deal with feature requests, it was all about what to put for but reports...)

Inizia esaminando il comando esistente tns resources splashes generate e il modo in cui la CLI invoca i comandi del dispositivo Android. Confronta questo flusso con adb shell screenrecording /sdcard/whatever.mp4, incluso il recupero del file risultante. Il lavoro è completato quando un sottocomando tns può avviare, arrestare ed estrarre una registrazione sul dispositivo.