Re-define loading for MalImg dataset

• Add dataset class for MalImg
• Re-define loading for MalImg

Fix datasets subpackage inclusion issue

• Include the pt_datasets.datasets subpackage in setup.

Reorganize dataset classes

• Move dataset classes to their own subpackage.

Use global random seed

• Use the global random seed set in a module instead of a fixed random seed.
• Reformat pt_datasets.COVID19Dataset class.

Fix slow loading

• Import umap only when needed to resolve slow loading import any import from the package.

Fix setup issues

• Update dependencies versions.
• Resolve download issue with Yelp using gdown.
• Rename IMDB to resolve download issue using gdown.

Add WDBC Dataset class

• Implement a torch.utils.data.Dataset class for WDBC dataset.

Fix package setup

Fixes

• Use shell gdown for downloading AG News and Yelp datasets
• Pin versions for llvmlite and numba

Add Yelp to supported datasets

• Add dataset class for Yelp text classification
• Add loader for training and test data for Yelp

Add loader function for IMDB dataset

Define loader function for IMDB training and test datasets