Allow ConsoleDriver to be customizable

[ryfu-msft]

The current DefaultConsoleDriver implementation is internal and makes it impossible to override any of the behaviors of the DefaultConsoleDriver class to fit my needs. Some suggestions that I have would be:

• Make the IConsoleDriver interface and DefaultConsoleDriver class public so that subclasses could inherit and override the method's behaviors.
• Plumb through a way to override the ConsoleDriver property , so that we could specify our own custom implementation of a ConsoleDriver

I believe that these changes builds on such a neat tool and would make the tool more fun and flexible for users to play around with.

[shibayan]

It is possible that it will be customizable in the future.

Since the implementation of ConsoleDriver is difficult considering the multiple language support and the interface is not completely solidified, I basically need your help to improve the default driver.