Mideface integration

[vferat]

Summary

It would be helpful to have support for mideface a command-line tool for defacing MRI scans in Freesurfer. This addition could enhance existing BIDS apps, such as BIDSonym.

If there is interest, I am willing to take care of its implementation.

[effigies]

Fine with me. It's also entirely fine to implement interfaces in the apps that need them, and not have to rely on nipype's release schedule. fMRIPrep and friends generally take this approach for new interface.