Allow the consumer to specify isCurrentLink and isCurrentNode for Sankey charts

[lukigarazus]

Is your feature request related to a problem? Please describe. I would like to be able to highlight all out-coming paths from a node, like this

Describe the solution you'd like Allow the consumer to provide their own definitions of isCurrentLink and isCurrentNode in the Sankey chart implementation.

Describe alternatives you've considered I considered using a more low-lever library to achieve this.