add support for sending cpu sparse tensors over rpc (#62794)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62794
This pr updates jit serialization to support pickling Sparse COO tensors.
This pr updates message.cpp to support Sparse COO tensors.
A bug was filed a few years ago https://github.com/pytorch/pytorch/issues/30807.
I tested the fix by adding sparse tensor tests to rpc_test.py and dist_autograd_test.py.
cc pietern mrshenli pritamdamania87 zhaojuanmao satgera rohan-varma gqchen aazzolini osalpekar jiayisuse agolynski SciPioneer H-Huang mrzzd cbalioglu gcramer23 gmagogsfm
Test Plan: Imported from OSS
Reviewed By: soulitzer
Differential Revision: D30608848
Pulled By: gcramer23
fbshipit-source-id: 629ba8e4a3d8365875a709c9b87447c7a71204fb
