Allow for WPF shown dialog ownership

[mwpowellhtx]

Currently, as far as I am aware, supports either "no ownership" or a WinForms form ownership. Neither is that appropriate in my use case, I am deploying into a WPF scaffold, so please allow for the System.Windows.Window based approach, i.e. as possibly via System.Windows.Application.Current.MainWindow, for instance, or any Window based point of origin. In my case, I actually do have a second Window source, but you get the point.

var d = new DirectoryObjectPickerDialog();
d.ShowDialog();