Fix: Validate Z-Coordinate Uniformity in DICOM Contour Processing

[SteEcker]

This PR is related to #377

Changes:

• Added verify_z_coordinates to check z-coordinate uniformity in plane['data'] for each DICOM contour.
• Integrated check before adding planes to the planes dict. If non-uniform z-coordinates are found, it halts processing and logs a warning.

Reason: Ensures DVH integrity by verifying z-coordinate uniformity within contours

[pep8speaks]

Hello @SteEcker! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers:

Comment last updated at 2024-03-14 13:37:17 UTC

[bastula]

Another suggestion: I think if we can write a test case with some dummy data to ensure we have code coverage that would make this PR fully complete. The test case can be included in the class TestRTStructureSet in similar method to test_structure_set_coordinates below:

https://github.com/dicompyler/dicompyler-core/blob/0ad6e71bdaf3cc76448b5dc78f8d29d1947a5f65/tests/test_dicomparser.py#L193-L204

It would probably best to create dummy structure data via the create_new_contour function in https://github.com/dicompyler/dicompyler-core/blob/0ad6e71bdaf3cc76448b5dc78f8d29d1947a5f65/tests/test_dvhcalc.py#L56