Add SCINet

[WenjieDu]

1. Model description

SCINet should be included in PyPOTS, and could start from the imputation task.

@inproceedings{liu2022scinet,
author = {LIU, Minhao and Zeng, Ailing and Chen, Muxi and Xu, Zhijian and LAI, Qiuxia and Ma, Lingna and Xu, Qiang},
booktitle = {Advances in Neural Information Processing Systems},
editor = {S. Koyejo and S. Mohamed and A. Agarwal and D. Belgrave and K. Cho and A. Oh},
pages = {5816--5828},
publisher = {Curran Associates, Inc.},
title = {SCINet: Time Series Modeling and Forecasting with Sample Convolution and Interaction},
url = {https://proceedings.neurips.cc/paper_files/paper/2022/file/266983d0949aed78a16fa4782237dea7-Paper-Conference.pdf},
volume = {35},
year = {2022}
}

2. Check open-source status

• The model implementation is publicly available

3. Provide useful information for the implementation

https://github.com/cure-lab/SCINet