Include templating infrastructure for Hierarchical Community-aware Graph Neural Network (HC-GNN)

[allaffa]

This paper describes a very elegant way to improve the performance of localized (short-range) message passing neural networks (MPNNs) by including global attention mechanics to model long-range interactions through hierarchical clustering of nodes
https://arxiv.org/pdf/2009.03717.pdf

Looking at the original implementation of HC-GNN
https://github.com/zhiqiangzhongddu/HC-GNN/blob/master/model.py
it seems like the inclusion of hierarchical MPNN can be easily templated over the underlying localized MPNN.
Since we are already tempting HydraGNN with respect to MPNNs, including Hierarchical MPNN as an additional level of may be very doable and not too difficult to perform.