[CLI] Manual watching the source changes

From @raffaeler on February 6, 2019 10:58

Is your feature request related to a problem? Please describe.
When tns run is started, it takes a while before deploying the application. For this reason I prefer to run in watch mode (tns run or tns debug).
Anyway, when you are doing more than a trivial change, it would be useful to manually trigger the compilation/deploy without stopping and re-running tns run or tns debug.

Describe the solution you'd like
When the terminal is in tns run or tns debug it can accept keyboard commands. It would be useful to add support for three commands while the terminal is watching:

• 's' key: suspend watching
• 'r' key: resume watching
• 'd' key: deploy while in suspended mode

Describe alternatives you've considered
Stopping and restarting tns run or tns debug is way too slow.

Copied from original issue: NativeScript/NativeScript#6865

Inizia dai punti di ingresso della CLI per tns run e tns debug, concentrandoti sul loro ciclo di vita in modalità watch e sulla gestione dell’input del terminale. Definisci come devono interagire il watching sospeso, il watching ripreso e il deployment manuale, quindi verifica che i comandi richiesti s, r e d funzionino senza arrestare il comando in esecuzione.