COMP: Fix generation of <target>.castxml.inc files for wrapping

All module generated the same ".castxml.inc" file.
This caused several issues:
- Each CMake configure step repeatedly overwrote .castxml.inc,
  causing a full rebuild of all wrapping related files because
  the XML descriptions were considered out-of-date.
- Wrapping of module itkVtkGlue failed, because it requires
  additional include directories that were removed by other modules.

This change makes each module now generates its own
"<module>.castxml.inc" file.

Author: AlexyPellegrini

Wrapping/macro_files/itk_auto_load_submodules.cmake

@@ -162,7 +162,7 @@ function(generate_castxml_commandline_flags)
   #Write compile definitions and include paths to file.  @CONFIG_CASTXML_INC_CONTENTS@ expanded in configure_file
   set(
     castxml_inc_file
-    "${WRAPPER_LIBRARY_OUTPUT_DIR}/castxml_inputs/${library_name}.castxml.inc"
+    "${WRAPPER_LIBRARY_OUTPUT_DIR}/castxml_inputs/${WRAPPER_LIBRARY_NAME}.castxml.inc"
   )
   configure_file(
     "${ITK_WRAP_CASTXML_SOURCE_DIR}/cast_xml.inc.in"