Can't initialize with a null SynchronizationContext.Current

[danielchalmers]

If SynchronizationContext.Current is null, VirtualDesktopProvider.Initialize will throw an InvalidOperationException: 'The current SynchronizationContext may not be used as a TaskScheduler.' at

https://github.com/Grabacr07/VirtualDesktop/blob/a6aba7088e6967e7ae81584bf16e9ae6e3bb4c96/source/VirtualDesktop/VirtualDesktopProvider.cs#L28-L29

This stops a blank console app from using VirtualDesktop.

Steps to reproduce:

• Create a new console app
• Target Windows 10 in app.manifest and add a reference to VirtualDesktop 3 beta
• In the main method, call VirtualDesktopProvider.Default.Initialize() (or a method that calls it for you like VirtualDesktop.GetDesktops()).

Workaround:
Call SynchronizationContext.SetSynchronizationContext first or use Initialize(TaskScheduler scheduler).