add a version of simple vit using flash attention

separate a simple vit from mp3, so that simple vit can be used after …

…being pretrained

release mp3, contributed by @Vishu26

double down on dual patch norm, fix MAE and Simmim to be compatible w…

…ith dual patchnorm

seeing a signal with dual patchnorm in another repository, fully inco…

…rporate

adopt dual patchnorm paper for as many vit as applicable, release 1.0.0

need simple vit with patch dropout for another project

add vit with patch dropout, fully embrace structured dropout as multi…

…ple papers are now corroborating each other

add vit with patch dropout, fully embrace structured dropout as multi…

…ple papers are now corroborating each other

offer 1d versions, in light of https://arxiv.org/abs/2211.14730