unwrapped_shapetype should use the wrapped object

[bernhard-42]

When testing docs/tutorial_joints.py the function write_svg in this file fails.
If I change this in topology/utils.py, it works

diff --git a/src/build123d/topology/utils.py b/src/build123d/topology/utils.py
index c876ba2..c1bbb1e 100644
--- a/src/build123d/topology/utils.py
+++ b/src/build123d/topology/utils.py
@@ -424,7 +424,7 @@ def unwrapped_shapetype(obj: Shape) -> TopAbs_ShapeEnum:
         if len(shapetypes) == 1:
             result = shapetypes.pop()
         else:
-            result = shapetype(obj)
+            result = shapetype(obj.wrapped)
     else:
         result = shapetype(obj.wrapped)
     return result

After this change, all build123d tests are still successful