Adapt the tools when modality == MRI

[delphinepilon]

If MODALITY = 'MRI' :

• remove all mention of hounsfield units (HU)
• create a hierarchical view of the files to be able to navigate between different series of a same sitting of a given patient (say T1w, T2w, etc)
• remove option of configuration for the semi-automatic PHE segmentation tool (not pertinent in the case of MRI since based on thresholding of HU)

[delphinepilon]

If MODALITY == 'CT' :

• keep tools using hounsfield units
• add option to have the semi-automatic PHE segmentation tool based on the following article
• add reference to this article, if not already present in the software

Volbers, B., Staykov, D., Wagner, I., Dörfler, A., Saake, M., Schwab, S., & Bardutzky, J. (2011). Semi-automatic volumetric assessment of perihemorrhagic edema with computed tomography. European journal of neurology, 18(11), 1323–1328. https://doi.org/10.1111/j.1468-1331.2011.03395.x