Followup fixes for "collapse/expand all subgroups"

[MichaelBuessemeyer]

This PR adds small fixes/changes to the behavior of the "collapse/expand all subgroups" feature.

If you expand all subgroups, the group itself is now also automatically expanded.
Previously it was possible to expand all subgroups of a collapsed group, but without expanding the group itself. This needed an extra "expand this group click".

Now the groups deeply check their children whether for expanded/collapsed groups. Previously only the immediate children were checked.

URL of deployed dev instance (used for testing):

• https://addcollapseallgroups.webknossos.xyz

Steps to test:

• open a skeleton tracing
• test the scenario shown in the picture of the issue Expand and collapse subgroups in trees tab followup #4166. In this specific scenario, it should be possible to still expand all children of the root group.
• use Expand all subgroups" on a collapsed group. The group itself should now also automatically expand itself.

Issues:

• fixes Expand and collapse subgroups in trees tab followup #4166

---

• [ ] Updated changelog
• [ ] Updated migration guide if applicable
• [ ] Updated documentation if applicable
• [ ] Adapted wk-connect if datastore API changes
• [ ] Needs datastore update after deployment
• Ready for review

[daniel-wer]

Fixes look very good to me :) I couldn't find a picture in #4162, but I tested the scenarios and fixes you outlined and they worked very well 👍

[MichaelBuessemeyer]

Sorry, the correct issue is #4166. I updated the description.