Testing cervical model on `dcm-brno` dataset

This issue describes the application of the [r20240523](https://github.com/ivadomed/model-spinal-rootlets/releases/tag/r20240523) model (for dorsal and ventral rootlets) on T2*w axial images (0.35 x 0.35 x 2.5mm) of C spine from the `dcm-brno` dataset (to be shared soon - [#326](https://github.com/neuropoly/data-management/issues/326)). The model has been tested on a few subjects from this dataset.

Here are examples of its use on a healthy subject and a subject with compression:

### Example of healthy subject:
- In this subject, the model segmented the rootlets quite well, but the spinal level order doesn't match - see below:


### Example of a subject with compression:
- In this subject, the model does not preform well (spinal level does not match) - see below:


Start by reviewing the r20240523 model results described for healthy and compressed subjects, then obtain the dcm-brno dataset referenced in #326. Compare segmentation quality and spinal-level ordering across the reported cases; done means documenting whether the observed mismatches are reproducible and what follow-up is needed.

Written by the indexing model from the issue text.