Allow ingress of segmentations in different spaces through --derivatives flag

[audreymhoughton]

A short summary of what you would like to see in NiBabies.

• allow ingress of files with this naming structure:
  sub-01_ses-A_space-T1w_desc-aseg_dseg.nii.gz
  sub-01_ses-A_space-T2w_desc-aseg_dseg.nii.gz
  sub-01_ses-A_space-T1w_desc-brain_mask.nii.gz
  sub-01_ses-A_space-T2w_desc-brain_mask.nii.gz
• with corresponding sidecars with the field ["SpatialReference"](SpatialReference key allowed values) giving the path to the file of the space the brain mask and segmentation are in
  Example: "SpatialReference": ["ses-X/anat/sub-Y_ses-X_run-1_T2w.nii.gz"]

Do you have any interest in helping implement the feature?

No :(

Add any additional information or context about the request here.

I can provide an example --derivatives dir with the corresponding inputs for testing if needed