BiasAnalyzerWidget - In concepts table, add scent for deeper interesting nodes

[violagoodacre]

Currently, when selecting interesting nodes to show in the concepts table, we stop going down when we find a node that matches our "interesting" rules. This enhancement is to continue looking down to the leaf nodes to see if any interesting nodes can be found further down. If one is found, a visual cue can be added to the selected interesting node to indicate this.