Added tag /*NXLT*/ for DynamoCoreWpf string

@ke-yu I added tag /*NXLT*/ for string in DynamoCoreWpf and put some strings there to resx file
@ke-yu these strings are not used for UI. The Start Page has 3 button: New, Open and New Custom Node which are created as: fileOperations.Add(new StartPageListItem(Resources.StartPageOpenFile, "icon-open.png")
These ButtonNames are used for the context data, I think we wont localize them