Fodf metrics should be a module

[karanphil]

I think scil_compute_fodf_metrics.py should be in a module in itself, and not inside the fodf module. The reason is, it would be nice to have a ssstfodf and a msmtfodf (damn no _!) module. A module fodfmetrics, just like the dtimetrics, would take as input any SH file.

[AlexVCaron]

Hi @karanphil ! I had a thought about this, and I think in the end we should sought something akin to what you propose. I really like the idea of having ssstfodf and msmtfodf as separate modules (and eventually memsmt !), it works with the logic of nf-scil, makes the modules interface a bit clearer and trying to bunch both in the same module could create a really ugly script.

However, as discussed, the metric script call will stay inside those modules. Its going to create duplication, but we'll handle this in future iterations. You can however still propose a module doing only metrics computation, for both DTI and SH, I am all good with that !