Feat/volumes

[pbarbarant]

Corrected PR strictly for the addition of volumetric features. Examples are now written in .py instead of .ipynb.

[alexisthual]

Almost there! 💪

Our CI is currently complaining because older examples make use of compute_lmds(), which was renamed to compute_lmds_mesh().

I have made a few suggestions, mostly typos and naming.

Here is a list of ideas to track for future reference:

• adding the method parameter to compute_lmds_mesh()
• checking what happens when our volumetric segmentation has more than one connected component

[alexisthual]

LGTM, thanks!