Optimize Swin UNETR (Project-MONAI#774)

* begin work

* checkpoint, added amp, todeviced, threaddataloader

* checkpoint, debug and profiling code

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* checkpoint experiment script

* ready, pending final checks

* applied autofixes

* done

* removed unnecessary files

* updated with set_track_meta

* tmp backup for profiling code

* removed test files

* updated json download

* updated explanation

* final profiling code backup

* remove test files

* updated json link and comments

Co-authored-by: Yuchen Xu <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people