Sparse tensor support

[JosiahParry]

Arrow C++ implementation has a sparse tensor implementation that supports CSR, COO, CSC, and CSF formats:
https://github.com/apache/arrow/blob/4eca50770f7f2c5938a676f0719fbfc8aae4803c/cpp/src/arrow/sparse_tensor.h#L52

It would be really great if the rust library could also support this. It would open up the ability to do sparse matrix math using arrow data—e.g. with faer, burn, or alternatives and make it very easy for data to cross the FFI boundary.

Specifically, my interest is in spatial statistics and GeoAI.