3D Linestyle support for visualisation and IFC export for BIM delivery

It would be very valuable to have DGN 3d Linestyle support in iTwin (as was available in Navigator) in both 3d and cross section views to allow for full support for DGN data and to allow users to add linear objects in their native models quickly to be used for review. These linear objects are also required for BIM delivery and therefore IFC export support would add a lot of power and value of iTwin as a platform to package IFCs for BIM delivery.