Feature request: Clustered Heatmap

Clustered heatmaps are widely used for visualization of multi-dimensional data and it is pretty useful for showing hierarchical relations and the patterns of features among the groups.

It is basically an extension of heatmap (`geom_tile`) with added **dendrograms** and group (or cluster) information with **colored bars next to the columns or rows** to visualize hierarchies and clusters within the dataset.

It is implemented as an extension package (`pheatmap`) for ggplot2.

e.g. (from https://slowkow.com/notes/pheatmap-tutorial/)


It is also implemented in seaborn (https://seaborn.pydata.org/generated/seaborn.clustermap.html)


It would be great to be able to use it in lets-plot.