Improved IFC Export of ChainData

The IFC export of ChainData has been improved. Objects are now split by type (chambers, pipes and other objects) and exported as IfcFlowTerminal, IfcFlowSegment and IfcGeographicElement respectively. Data fields are placed in separate Property Sets (Psets), and objects are named automatically based on ID, pipe type/dimension or data type description.

Note that GUIDs are regenerated on each export, and field names from SFI are used directly without remapping.