IFC Mesh Separate - fix bug in 52af302bef separating multiple elements

Forgot to clear selection after processing each object, it could have led to incorrect results since mesh.separate is applied to the selection later.

src/bonsai/bonsai/bim/module/geometry/operator.py

@@ -119,6 +119,7 @@ class OverrideMeshSeparate(bpy.types.Operator, tool.Ifc.Operator):
                 self.separate_element(context, element, obj)
             else:
                 non_ifc_objects.append(obj)
+            bpy.ops.object.select_all(action="DESELECT")
 
         if should_reload_representation:
             rep_obj = tool.Geometry.get_geometry_props().representation_obj