Wish: An option to only export rooms "visible in view"

**We're missing a possibility to select what rooms to export.**

Today, if we want to export only parts of the project file, for example only the first level, or only the objects in a certain workset, we can control this for model elements by using "Export only elements visible in view". We're missing the same possibility for rooms. It's all or nothing for rooms.

**Alternative 1**, hopefully quite simple to achieve:
Make Revit respect open/closed worksets when exporting. That way we could filter out the rooms to export/not export by placing them in different worksets. This is not a perfect workflow, but would be better than what we have today.

**Alternative 2**, requires changes to room behavior in Revit:
Make rooms visible in 3D views and make them follow "Export only elements visible in view". This would be the perfect workflow.

No file or test is named in the issue. Start by locating the room-export path in the C# IFC exporter and examining how worksets and “Export only elements visible in view” are handled; done means rooms can be filtered during export through a supported workflow.

Written by the indexing model from the issue text.