Add support for Windows Phone apps

[imsardine]

This project aims for being a single tool for test automation of all kinds of Windows applications, therefore the support for Windows Phone apps should be added as well.

The concept has been proved by 2gis/Winium.StoreApps and Appium (How to Automate Windows Phone 8.1). However, both solutions rely on Coded UI Tests (CUITs) which is only available in Visual Studio Premium / Ultimate and therefore cost money.

All findings should be documented first.