MAGNOLIA-6893 fixed this problem for move actions but the same problem is there for:
- adding node by code (Node#addNode action)
- import (hopefully will be fixed by fixing addNode, to be checked)
MAGNOLIA-6893 already introduced a session wrapper, we just need to add a node wrapper.
This is due to a bug in jackrabbit which allows same name sibling at root even though same name siblings are disabled by repo config.