Write out cortex mask used for CIFTI creation

[tsalo]

What would you like to see added in fMRIPrep?

One of the inputs required to create fsLR-space GIFTIs in bold_fsLR_resampling_wf is the cortex_mask input, which comes from hcp_morphometrics_wf.outputnode.roi. As far as I can tell, this is the only file needed to map from anatomical-space BOLD data to fsLR-space GIFTIs that isn't written out by fMRIPrep.

Do you have any interest in helping implement the feature?

Yes

Additional information / screenshots

No response