Replace any remaining references to `dataset` with `block`

With the work done in #233 , the `DataSet` class was removed in favour of using `DataSetBlock` directly to create a block. In that change it was attempted to replace all uses of `dataset` with `block` (in function parameters primarily) to reduce confusion, as well as because a block now is the fundamental data object that is worked with in httomo.

There were many references to `dataset` so it was bound to happen that a few were missed. There are not many references to `dataset` left, maybe only this one https://github.com/DiamondLightSource/httomo/blob/feature/transparent-file-store/httomo/method_wrappers/generic.py#L207, but it would be good to finalise this replacement at some point, to minimise confusion moving forward.