guids in property set xmls

Probably not a big deal but in ifc4 xmls files for property sets used to define some guid that was used later in the .ifc pset templates. That way guid should stay consistent and diff check between templates will contain only actual changes and not guid


Start by locating the IFC4 XML files for property sets and the corresponding .ifc property-set templates mentioned in the issue. Compare their GUID handling and the resulting template diffs; done means GUIDs remain consistent so diffs show only actual property-set changes.

Written by the indexing model from the issue text.