PR: Gutter material not exported

### Problem Description

As the title says: when exporting a gutter that has a material assigned, the resulting ```IfcPipeSegment.GUTTER``` entity has no material assigned to it.

Tested for IFC2x3 CV2 as well as IFC4 RVArch. Not a regression btw, happens in 23.2.5 as well.

Minimal model to reproduce: https://github.com/andydandy74/MyIssues/blob/master/RevitIFC649/132_IFC_NoGutterMaterial.rvt

### Revit Version

2023.10.x

### IFC for Revit Addon Version

23.3.0

### Windows Version

10 22H2

Start with the linked Revit model and reproduce the export for IFC2x3 CV2 and IFC4 RVArch using the stated Revit and IFC for Revit versions. Inspect the resulting IfcPipeSegment.GUTTER entity and trace where its assigned material should be exported; done means the gutter material is present in both outputs.

Written by the indexing model from the issue text.