Change default space label to None

[michaelmack]

Is your feature request related to a problem? Please describe.
The current default space is set to the default space used in fmriprep (i.e., MNI152NLin2009cAsym), which is very reasonable. There is also the option to change the space label to use data in other spaces. What is missing is the option to run nibs on the minimally preprocessed BOLD data in the native participant space, which in the current version of fmriprep is created without a space label in the filename (e.g., sub-001_task-learn_run-1_desc-preproc_bold.nii.gz).

Describe the solution you'd like
I'm not sure about this, but I think if the space label option is set to None, the BOLD data in native participant space would be selected in the workflow. This can be done in the python interface, but not from the command line. If the default option for the space label was set to None, maybe this would allow for this type of functionality.

Describe alternatives you've considered
An alternative approach would be to specifically define a --space-label keyword for native participant space that would then be caught with a condition statement to set the space label to None. This would keep the current default behaviour, so maybe is a better solution.