Test the new feature linkpath on objects

[hugtalbot]

A new feature on all SOFA objects object.linkpath now returns a type LinkPath (not a string) to provide directly path of objects in the scene and connect components. This feature is being tested and either keep as is, replaced (a string used as object.path) or removed.

Associated PR : #265

[damienmarchal]

I think this is now merged since a long time. We can close the issue.