IfcPipeSegment Length twice

Length of IfcPipeSegment appears both in [Pset_PipeSegmentTypeCommon ](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/Pset_PipeSegmentTypeCommon.htm)and [Qto_PipeSegmentBaseQuantities](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/Qto_PipeSegmentBaseQuantities.htm).

I then looked at the PSD definition, but didn't find that Length there:
https://github.com/buildingSMART/IFC4.3.x-development/blob/master/reference_schemas/psd/Pset_PipeSegmentTypeCommon.xml

- [ ] I would remove the Length in Pset_, keep it in Qto_ only.
- [ ] How is this Length assigned to Pset_ if not through PSD?

Compare the Length entries in the linked Pset_PipeSegmentTypeCommon and Qto_PipeSegmentBaseQuantities definitions with reference_schemas/psd/Pset_PipeSegmentTypeCommon.xml. Determine where the Pset property is assigned and whether the duplicate should be removed; done means the source and intended definition are resolved and the relevant specification data is updated.

Written by the indexing model from the issue text.