Feature Request: Delete segments

[jwvanderbeck]

It would be nice to be able to delete segments directly in the editor rather than having to save to PNG then do it in a paint program.

Deleting segments has a lot of uses, here are some:

1. On images where certain body parts are out of frame
2. On images where body parts occlude others, ControlNet doesn't handle this well and removing the segments that are behind produces better results
3. On complex poses, especially with overlaps or large foreshortening, ControlNet suffers and deleting key segments can help a lot
4. Using some segments but not others allows you to "pin" certain body parts while still allowing random variation in others during generation