Replace custom ElasticDeformation by torch implementation

We might be able to use torchvision's ElasticTransform instead of our custom ElasticDeformation implementation for data augmentation. It would be more robust and work on batches.

https://pytorch.org/vision/stable/generated/torchvision.transforms.ElasticTransform.html#torchvision.transforms.ElasticTransform

Comparison images will follow, file attachments appear to be broken at the moment.