Revit exports `IfcOpeningElement` shape representation with identifier 'Body'

The lines below confirm the statement in the title:
```
#900350= IFCSHAPEREPRESENTATION(#120,'Body','SweptSolid',(#900349));
#900352= IFCPRODUCTDEFINITIONSHAPE($,$,(#900350));
#900360= IFCOPENINGELEMENT('3Fzw5R94jDrxmE5vnc86XP',#42,'arc_Drehfenster 1-flg - Variabel:334_DF_1flg:986852:1',$,$,#900358,#900352,'986852',.OPENING.);
```
The file is RV 1.2
`FILE_DESCRIPTION(('ViewDefinition [ReferenceView_V1.2]','ExchangeRequirement [Architecture]'),'2;1');`
which means that only Reference geometries are allowed. See:
https://standards.buildingsmart.org/MVD/RELEASE/IFC4/ADD2_TC1/RV1_2/HTML/link/ifcopeningelement.htm

Copied specification below:

>Body SweptSolid PolyCurve Geometry
>The Body SweptSolid PolyCurve Geometry concept (defined at a supertype) does NOT apply to this entity.
>Body Tessellation Geometry
>The Body Tessellation Geometry concept (defined at a supertype) does NOT apply to this entity.
>Body Geometry General
>The Body Geometry General concept (defined at a supertype) does NOT apply to this entity.

Start by tracing the Revit IFC export path for IfcOpeningElement and the code that assigns shape-representation identifiers. Compare the generated IFC snippet with the linked IFC4 Reference View 1.2 specification; done means the export no longer emits the disallowed Body representation for this entity.

Written by the indexing model from the issue text.