[ENH]: Split the layering steps

[marcobarilari]

Is there an existing issue for this?

• I have searched the existing issues

New feature

Not sure in which step would be better to manually clean the segmentation, but it seems to that the output of the `cruise` is the best target for manual adjustment. 

I would propose to split the `extract brain region` + `cruise` steps to the actual layering last step. 

Similarly to what it happens in the segmentation script fro `skullstrip` and `segmentation`

Unclear documentation

No response