ENH: Tedana-friendly ME derivatives

[effigies]

Changes proposed in this pull request

• Add --output-echos flag to indicate that BOLD series should be output for individual echos.

TODO:

• Figure out what's going on with SDC. Currently all the logic is in a branch that assumes no SDC.
• ...

Beginning to address #2542.
Builds on #2574.

Documentation that should be reviewed

[pep8speaks]

Hello @effigies! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2021-11-01 19:12:09 UTC

[effigies]

Need to update the expected derivatives for ds000210 and do a style pass, but otherwise I think this is ready for review. Definitely did some quick-and-dirty patches to get all of the metadata in, which could stand some thoughtful cleaning up.

[effigies]

This is ready and can either go in 21.0.0 or wait for the next series.

[oesteban]

My vote goes to 21.0.0, FWIW 👍