BUG: Add __all__ to itk.support.init_helpers

Avoid adding the imports into the `itk` package namespace.

Wrapping/Generators/Python/itk/support/init_helpers.py

@@ -2,6 +2,17 @@
 from enum import IntEnum, unique
 from typing import Union
 
+__all__ = [
+    "auto_not_in_place",
+    "AutoProgressTypes",
+    "auto_progress",
+    "terminal_progress_callback",
+    "terminal_import_callback",
+    "simple_import_callback",
+    "simple_progress_callback",
+    "force_load",
+]
+
 # The following line defines an ascii string used for dynamically refreshing
 # the import and progress callbacks on the same terminal line.
 # See http://www.termsys.demon.co.uk/vtansi.htm