WIP [ENH] Add singleshell benchmarking recon workflow

[mattcieslak]

cc @ameliecr

We're working on a project to compare tractometry methods using different reconstruction methods on single-shell acquisitions. There are too many initial steps that need to be shared for autotrack to use the simple recon spec json format. So this workflow would break up the initial calculation of qa and iso, and registration into separate steps.

Relevant thread: https://groups.google.com/g/dsi-studio/c/emMz-K8ewlo

[tsalo]

@mattcieslak do you want to reproduce this on QSIRecon?

[mattcieslak]

yes, this will be important for the clinical data processing. @smeisler this may be a better PR to get started on than synb0 for now since we'll need it for the clinical dmri. It is supposed to add @ameliecr's work on ss3t-autotrack into qsirecon

[tsalo]

I've opened PennLINC/qsirecon#171 for this and linked to this PR.