Handle self conflicting empty group pathes

[Skaiir]

Describe the Bug

#808 (review)

An empty path in a group can conflict when setting its value to that of the path of its direct child. This isn't majorly problematic because the workaround is simple, see linked issue for a more visual example.

Steps to Reproduce

1. Add a group
2. Add a checkbox inside that group
3. Set the checkbox's key to test
4. Set the group's key to test
5. A conflict is triggered, disallowing the configuration
6. Set the group's key to test1
7. Set the group's key back to test
8. Works as e

Expected Behavior

5. No conflict should be triggered, path validation shouldn't consider direct children for groups.

This can most likely be fixed the same way as keys by temporarily de-registering all the paths associated with the group before doing the check (search // unclaim temporarily to avoid self-conflicts)