Handle duplicate slices

[Zhack47]

While using the rt-Utils library for RTstruct conversion, I noticed that:

If slices are present multiple times in the dicom path, they will be loaded as many times , resulting in a size N times bigger in the z-axis than it should be.

N being the number of times a slice is repeated

I fixed this by ensuring unique SOPInstanceUID in the list of files inside the load_dcm_images_from_path function:

def load_dcm_images_from_path(dicom_series_path: str) -> List[Dataset]:
    unique_sop_UIDs = []  # New
    series_data = []
    SOPInstanceUID_tag = Tag(0x00080018)  # New
    for root, _, files in os.walk(dicom_series_path):
        for file in files:
            try:
                ds = dcmread(os.path.join(root, file))
                if hasattr(ds, "pixel_array") and ds[SOPInstanceUID_tag] not in unique_sop_UIDs:  # Partly new (second check)
                    series_data.append(ds)
                    unique_sop_UIDs.append(ds[SOPInstanceUID_tag])  # New
            except Exception:
                # Not a valid DICOM file
                continue

    return series_data

If this is considered useful I can submit a pull request

Regards
Zhack