add alluvial/ranking chart type (feature request)

Some R packages allow to easily generate simple ranking/alluvial graphs (python libraries are more complex / sankey diagrams for this purpose)
It would be great to integrate such fonctionnality to obtain graphs like this one


No files, tests, or entry points are identified in the issue. Start by reviewing the existing chart types and visualization architecture, then define the expected ranking/alluvial behavior from the example before determining how it should be tested and when the feature is complete.

Written by the indexing model from the issue text.