BIM: Fix ArchBuildingPart not moving child object base (#27237)

When a child (e.g. a Wall) of an ArchBuildingPart (e.g. of a Level)
had both 'Move With Host' and 'Move Base' enabled, it failed to move
the base (e.g. Line) of the child, and only displaced the child
itself (effectively ignoring the 'Move Base' setting).

Example project structure:

Level
|
+- Wall ('Move With Host' = true, 'Move Base' = true)
   |
   +- (base of Wall) Line

src/Mod/BIM/ArchBuildingPart.py

@@ -44,6 +44,7 @@ import Draft
 import DraftVecUtils
 
 from draftutils import params
+from draftutils import utils
 
 if FreeCAD.GuiUp:
     from PySide.QtCore import QT_TRANSLATE_NOOP
@@ -356,7 +357,9 @@ class BuildingPart(ArchIFC.IfcProduct):
                 deltar = obj.Placement.Rotation * self.oldPlacement.Rotation.inverted()
                 if deltar.Angle < 0.0001:
                     deltar = None
-                for child in self.getMovableChildren(obj):
+                children = self.getMovableChildren(obj)
+                children = utils._modifiers_filter_objects(children, False)
+                for child in children:
                     if deltar:
                         child.Placement.rotate(
                             self.oldPlacement.Base,