✨ Generalize N4 bias correction option for all coregistration inputs

[sgiavasis]

Related problem

C-PAC currently allows users to select N4 bias field correction for the single-volume sbref input to BOLD-to-T1w coregistration, but only for the Mean Functional option of this input. C-PAC has three separate options for this input, and you can't select to N4 bias correct for the other two.

Proposed feature

Pull the N4 bias correction option for coregistration input out of that tier and make it standalone, such that it is applied to whatever sbref is generated, regardless of the option selected - not just for Mean Functional.

Acceptance criteria

• Enable N4 bias correction for coregistration input and confirm the tool has been run on either Selected Functional Volume or fmriprep-reference.
• Change the pipeline configuration schema such that the N4 option is no longer just under the Mean Functional sub-section.

Alternatives

No response

Additional context

No response