IfcGeometricRepresentationContext's TrueNorth attribute should be described as purely reference only

https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcGeometricRepresentationContext.htm says this:

> The TrueNorth attribute should be provided, if the y axis of the WorldCoordinateSystem does not point to the global northing. Direction of the true north, or geographic northing direction, relative to the underlying project coordinate system as established by the attribute WorldCoordinateSystem. It is given by a 2 dimensional direction within the xy-plane of the project coordinate system. If not resent, it defaults to [0.,1.] - i.e. the positive Y axis of the project coordinate system equals the geographic northing direction. The direction is provided within project coordinate system and identifies the true north direction.

I don't think this makes sense anymore. The map conversion X axis abscissa/ordinate point to **Grid North**. Whether or not a project contains an indicative "reference" **True North** (true north is not a constant, but may be sampled at a point) should be an independent project decision, nothing to do with "WorldCoordinateSystem".

For example, it contradicts with the paragraph below:

> If a conversion to a geographic coordinate system is included by virtue of the HasCoordinateOperation attribute, then the TrueNorth attribute shall be omitted or included only for informational purposes. It shall not be added to any transformation already applied by an [IfcCoordinateOperation](http://localhost:5000/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCoordinateOperation.htm).

Proposal: remove the paragraph starting with "The TrueNorth attribute should be provided" and deprecate WorldCoordinateSystem.