Update type hints to the new style

[warner-benjamin]

Update type hints to the new style in the following notebooks:

• 00_torch_core.ipynb
• 01a_losses.ipynb
• 03_data.core.ipynb
• 04_data.external.ipynb
• 06_data.block.ipynb
• 08_vision.data.ipynb
• 09_vision.augment.ipynb
• 09c_vision.widgets.ipynb
• 12_optimizer.ipynb
• 13_callback.core.ipynb
• 18_callback.fp16.ipynb
• 19_callback.mixup.ipynb
• 20_interpret.ipynb
• 24_vision.gan.ipynb
• 32_text.models.awdlstm.ipynb
• 33_text.models.core.ipynb
• 37_text.learner.ipynb
• 41_tabular.data.ipynb
• 42_tabular.model.ipynb
• 43_tabular.learner.ipynb
• 99_pytorch_doc.ipynb

[warner-benjamin]

I am also working on 06_data.block.ipynb

[dienhoa]

I'll work on 09_vision.augment.ipynb

[miwojc]

I'll work on 08_vision.data.ipynb

[Karthik-d-k]

I'll work on 41_tabular.data.ipynb

[marii-moe]

Working on 18_callback.fp16.ipynb

[omer-dor]

I will start with the one I worked on during the sprint: 09c_vision.widgets.ipynb