MONAI transforms can't only support `Tensor` backend

Is your feature request related to a problem? Please describe. Currently, some transforms only support Tensor backend, which will break previous numpy based transform chains. Need to update them to make sure all the transforms support both numpy and Tensor backends or only numpy backend.

[rijobro]

Ok, sounds reasonable.

[rijobro]

My vision is that, if necessary, each transform will convert to the correct image type. That is to say, if the computation requires torch.Tensor and input is numpy, then convert. To reduce the number of conversions, I don’t convert back to the original type at the end of the transform. This means that all transforms will need to be able to accept torch or numpy input. By the time I’ve finished updating all transforms, this will be the case.

However, it seems that since we’re currently part-way through the changes, some transforms will be in chains that would have originally received numpy input, but now they’re getting torch tensors instead.

I suppose as a temporary fix, we could modify all problematic transforms to have something like this at the start of the __call__ function:

def __call__(img):
    img, *_ = convert_data_type(img, np.ndarray)
    ...