[Bug]: Broken behavior for deleting fiducials

[mxgrey]

Before proceeding, is there an existing issue or discussion for this?

• I have done a search for similar issues and discussions.

Description

Deleting a fiducial that belongs to a group will permanently block any other fiducial in its drawing from being able to join that group.

We're not handling the case where fiducials get deleted and their group needs to be made re-available. And then there's also no mechanism to recover the group for the drawing.

We should have a better pipeline for deleting items that doesn't rely so much on Bevy's despawning feature. Ideally that pipeline should:

• Ensure we can properly clean up situations like this one
• Allow us to support an undo buffer, so things aren't permanently deleted