Expose mem_manager and save_to_json functions.

aidge_core/__init__.py

@@ -11,4 +11,6 @@ from aidge_core.aidge_core import * # import so generated by PyBind
 import aidge_core.export_utils
 import aidge_core.utils
 from aidge_core.aidge_export_aidge import serialize_to_cpp
+from aidge_core.show_graphview import gview_to_json
+from aidge_core.mem_info import *
 from ._version import *