clan_cli: move __init__.py into cli.py

This helps to reduce import cycles in python
If ANY python module from clan_cli is imported all the imports of the __init__.py are executed leading to a lot of cycles

pkgs/clan-cli/clan_cli/__main__.py

@@ -1,4 +1,4 @@
-from . import main
+from .cli import main
 
 if __name__ == "__main__":
     main()