Add Next-ViT

[XiaXin-Aloys]

Hi, we are a group of engineers from Bytedance Inc. This year, our team published the work: "Next-ViT: Next Generation Vision Transformer for Efficient Deployment in Realistic Industrial Scenarios"(https://arxiv.org/abs/2207.05501) (https://github.com/bytedance/Next-ViT). We'd like to add our work to this amazing framework of Pytorch image models. Thank you very much.