Support QML debugging with non-MSBuild projects

https://www.qt.io/blog/2019/01/21/qt-visual-studio-tools-2-3-1-released describes the addition of QML debug integration into Visual Studio. mecfc mentioned in the comments that 'CMake projects in Visual Studio, using the non-MSBuild "open folder" approach, will be supported in a future release.'

This ticket is to track the addition of this support.