Add error message for impossible roi request to ZeissDataReader and fix sign error when negative values passed to ROI

[lauramurgatroyd]

Description

• If the ROI bound is larger than the axis, a ValueError will be raised. Previously, it would go on to crop the geometry but not the data and would throw an error when trying to create the AcquisitionData to return, which was not clear to the user what was wrong.
• If a negative number is given to the ROI, previously this was subtracted (so double negative) whereas it should've been added (single negative) to the total axis length.

Closes #2240

Example Usage

Contribution Notes

• The content of this Pull Request (the Contribution) is intentionally submitted for inclusion in CIL (the Work) under the terms and conditions of the Apache-2.0 License
• I confirm that the contribution does not violate any intellectual property rights of third parties

Changes

Testing you performed

Please add any demo scripts to https://github.com/TomographicImaging/CIL-Demos/tree/main/misc

Related issues/links

Checklist

• I have performed a self-review of my code
• I have added docstrings in line with the guidance in the developer guide
• I have updated the relevant documentation
• I have implemented unit tests that cover any new or modified functionality
• CHANGELOG.md has been updated with any functionality change
• Request review from all relevant developers