Import/Export of Multi-Segmented Grids

I tried to import IFC with grids, with one of them being `IfcPolyline` with an array of Points (N > 2). But log says
```
#121: ERROR: Found multiple curve segments for grid line, ignoring all but first.
```

I tracked it up to https://github.com/Autodesk/revit-ifc/blob/36d7eea39748f0addaba872596eb19329790bda7/Source/Revit.IFC.Import/Data/IFCGridAxis.cs#L375

Same thing happens with `IfcSegmentedCurve`. Shouldn't they be imported as single Multi-Segmented grid objects rather than being trimmed of all segments but first?

Read Source/Revit.IFC.Import/Data/IFCGridAxis.cs around line 375 and trace how IfcPolyline and IfcSegmentedCurve grid axes are handled. Reproduce the issue with an IFC grid containing multiple points or segments, then verify import preserves the complete multi-segment grid instead of logging and retaining only the first segment.

Written by the indexing model from the issue text.