Adding LibraryView prototype files into DynamoCore project

This pull-request is initial in series of pull-requests connected with adding new design prototype into Dynamo.

@Benglin, please review.

The code almost not changed of version you send me by email. Please check if I added files in correct places and namespaces. Thank you.
Since we're already in ```DynamoCore```, please remove this method and make use of the existing one ```WPF.FindUpVisualTree```.