* testing dataloader
* matching dataloader implementation for unet3d
* remove comments
* clean up dataloader
* add cookie and cleanup
* use shm_path when creating SharedMemory
* add support for testing resnet and unet3d dataloaders
* update dataset test to return preprocesed data directory in prep for dataloader testing
* pass preprocessed dataset directory properly
* update loader function for dataloader
* add shuffling on indices
* update shm name
* more cleanup for unet3d dataloader
* remove changes to tests
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Co-authored-by: chenyu <chenyu@fastmail.com>