Update pipelines to match changes to image saver and rescaler methods

[yousefmoazzam]

These changes are needed on the httomo side to accommodate when the following changes are released in httomolib and httomolibgpu (ie, when these changes make their way into the conda packages that httomo installs during CI):

• Rescale to int cpu/gpu agnostic httomolibgpu#157
• Imagesaver changes httomolib#17

Checklist

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have made corresponding changes to the documentation

[yousefmoazzam]

The two failing tests are both related to how the image saver wrapper is auto-inserted after the method that has the sweep:

test_pipeline.py::test_run_gpu_pipeline_sweep_cor
test_pipeline.py::test_run_gpu_pipeline_sweep_paganin

The tests fail because the image saver method has been auto-inserted, but the input data has not been rescaled (the image saver no longer supports rescaling the input). Thus, it would seems like, for sweeps, the rescale_to_int method needs to be auto-inserted along with the save_to_images method to fix this issue.

[dkazanc]

Looks all fine, thanks for that! Slightly disappointing that we need to auto-insert always with perc_range_min: 0.0 and perc_range_max: 100.0, but at the moment there is not much we can do about it. An alternative can be to incorporate a possibility of saving 32-bit floating point tiffs (we will wait if this is needed).

I hope that in future when we have a percentile based scaling our auto range can be on a safer side by defaulting to say [5,95] range or something. This should help to avoid dragging some outliers into the rescaled data.