ENH: Simpler support for passing ImageList as a Python list

This if a follow-up to f7e72cf.
Mimics InsightSoftwareConsortium/ITK@d6c69f5#diff-3ef0e8629fa32eaa30902d2f10fb7757b3341d241576373bd0cae3415c05188cR11

wrapping/itkANTsGroupwiseRegistration.wrap

@@ -1,16 +1,7 @@
-# Needed for passing a list of images via a setter, see commit message here:
-# https://github.com/InsightSoftwareConsortium/ITK/pull/526/commits/d6354b9d06457b740d8497595572c908461b5c1c
-set(import_text "%include ${WRAPPER_MASTER_INDEX_OUTPUT_DIR}/python/itkImage_ext.i\n")
-string(FIND ${ITK_WRAP_PYTHON_SWIG_EXT} ${import_text} pos)
-if(${pos} EQUAL -1)
-  string(PREPEND ITK_WRAP_PYTHON_SWIG_EXT "${import_text}")
-endif()
-unset(import_text)
-# the rest of the file is normal wrapping specification
-
 itk_wrap_class("itk::ANTsGroupwiseRegistration" POINTER)
   foreach(d ${ITK_WRAP_IMAGE_DIMS})
     foreach(t ${WRAP_ITK_SCALAR})
+      string(APPEND ITK_WRAP_PYTHON_SWIG_EXT "DECL_PYTHON_STD_VEC_RAW_TO_SMARTPTR_TYPEMAP(itkImage${ITKM_${t}}${d}, itkImage${ITKM_${t}}${d}_Pointer)\n")
       itk_wrap_template("F${ITKM_I${ITKM_${t}}${d}}" "${ITKT_I${ITKM_${t}}${d}}, ${ITKT_I${ITKM_F}${d}}, float")
       itk_wrap_template("D${ITKM_I${ITKM_${t}}${d}}" "${ITKT_I${ITKM_${t}}${d}}, ${ITKT_I${ITKM_F}${d}}, double")
     endforeach()