Name the center mark/line action body in the associative data rows

The codec now reads AcDbCenterMarkActionBody and AcDbCenterLineActionBody
as a SmartCenterActionBody variant; the Properties associative-data rows
label it "Center Mark/Line Action". The codec dependency is patched to the
fork commit that adds the variant.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/entities/object_data.rs

@@ -903,6 +903,7 @@ fn associative_data_name(data: &AssociativeData) -> &'static str {
         AssociativeData::ArrayParameters(_) => "Array Parameters",
         AssociativeData::ArrayActionBody(_) => "Array Action",
         AssociativeData::ArrayModifyActionBody(_) => "Array Modify Action",
+        AssociativeData::SmartCenterActionBody(_) => "Center Mark/Line Action",
         AssociativeData::DimensionAssociation(_) => "Dimension Association",
         AssociativeData::PersSubentManagerStatic(_) => "Static Subentity Manager",
         AssociativeData::ViewRepActionBody(_) => "View Representation Action",