WorldCoordinateSystem talks about a project base point and survey point

From the docs of IfcGeometricRepresentationContext: https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcGeometricRepresentationContext.htm

> If an geographic placement is provided using [IfcMapConversion](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcMapConversion.htm) then the WorldCoordinateSystem atttibute is used to define the offset between the zero point of the local engineering coordinate system and the geographic reference point to which the [IfcMapConversion](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcMapConversion.htm) offset relates. **In preferred practise both points (also called "project base point" and "survey point") should be coincidental**. However it is possible to offset the geographic reference point from the local zero point.

This sounds like Revit specific language and doesn't make sense to me. Other software don't have a "project base point" and "survey point". In real life your model has a 0,0,0 point (which IfcMapConversion handles any conversion to map coordinates) and that's it. There isn't a single special "survey point".

Proposal: remove this language and deprecate WorldCoordinateSystem

Ping @pjanck

Start by reading the linked IfcGeometricRepresentationContext and IfcMapConversion documentation, focusing on the WorldCoordinateSystem wording and its relationship to the geographic reference point. Determine the agreed replacement wording and whether deprecating WorldCoordinateSystem is in scope; done requires an accepted specification decision and corresponding documentation update.

Written by the indexing model from the issue text.