Display line/col of error nodes after validation

[labra]

The new implementation of ShEx-s reports information about the position of the node that has failed in the JSON API information object.

This position can be used to display in the RDF editor the nodes that have failed.

It may require to adapt YaTE's code to allow this option although it could also be done from the external window that shows the editor highlighting the position.

A similar option will be added to ShEx so we could also point to the shapes that have failed so it would also be interesting to check if it is possible to add this option to YASHE tool.