Improve support for Visual Studio Code

Many developers around the world use Visual Studio Code for their workflows. Python in particular is a popular language for this. It is also used by developers inside The Qt Company.

Consequently, it may be worthwhile to ensure that setting up a workflow to develop for/with PySide on Visual Studio Code is as seamless as possible. This can include providing configurations where possible, tutorials where not, and integrations with the IDE such as automatic unit test discovery, QML language support, or others.

Of course, this kind of support and integrations can be added for other IDEs as well, e.g., PyCharm. 

This user story will refer to related Gerrit changes are they are created.