ENH: Add movement compensation

[larsoner]

Before merging …

• Changelog has been updated (docs/source/changes.md)

Adds basic movement compensation capability. Part of #574, which I've fleshed out into additional steps

The if run == runs[0]: conditional in _get_raw_paths that makes it add noise and rest runs really makes the logic here convoluted. In my next PR I'll try to split that out entirely so that it's cleaner. I thought about doing it here but I think it would make it harder to review, and it'll be nice to have the ds004229-with-MC case in place already.

[larsoner]

The code here is ready for review. Something is funky with the actual movecomp that I'm still investigating but hopefully it'll be a small fix that I can put on top of what's here already:

• main
• PR

So @hoechenberger feel free to review and conditionally approve if you're happy with the code changes in principle, then I'll fix whatever is messing up the data and merge

[larsoner]

Okay this finally works, here is the report (which is much better than main where the ERF just shows an artifact!):

• https://output.circle-artifacts.com/output/job/d0fc174f-aa0b-498b-8e7a-4b741d05465f/artifacts/0/site/examples/ds004229/sub-102_task-amnoise_report.html

Ready for review/merge from my end.

[larsoner]

Approved so I'll merge and keep moving!