Move Documentation on `IfcTesselatedFaceSet.Closed` to the entity

Currently, the subtypes `IfcTriangulatedFaceSet` and `IfcPolygonalFaceSet` hold this text:
"
Depending on the value of the inherited attribute Closed the instance of "either polygonal or triangulated face set link" represents:

if TRUE, a boundary representation (or B-rep);
if FALSE, a face based surface representation.
"

Since the relocation of the `Closed` attribute to the base entity, I would propose moving that documentation snippet also and remove it from the subtypes.

Locate the documentation for IfcTesselatedFaceSet and its subtypes IfcTriangulatedFaceSet and IfcPolygonalFaceSet. Move the quoted explanation of the inherited Closed attribute to the base entity, remove it from both subtypes, and verify that the text appears only in the intended location.

Written by the indexing model from the issue text.