Add "hide/show other trees" to tree context-menu

[hotzenklotz]

There already is a functionality in webknossos to "Hide all inactive trees", i.e. toggle the visibility of all other trees but the currently selected one. This feature is bound to keyboard hotkey 2.
In this PR, I exposed this functionality through the right-click context menu for each tree/group.

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• Create a skeleton annotation with a few trees and groups.
• Right-click on a tree/group and select "Hide/Show all other trees"
• The selected tree/group should now:
  • be selected (blue background behind name)
  • the visibility of all tree/groups should be toggled
• Right-click again to undo

Issues:

• no issue

---

(Please delete unneeded items, merge only when none are left open)

• Updated (unreleased) changelog
• Updated (unreleased) migration guide if applicable
• Updated documentation if applicable
• Adapted wk-connect if datastore API changes
• Adapted wk-libs python client if relevant API parts change
• Needs datastore update after deployment
• Ready for review

[philippotto]

Works mostly well 👍 I think, it's worth an entry in the changelog.

Some observations which are not blocking in my opinion, though:

• the context menu does not close when using the new item. it's a bit weird, but in line with most of the other items, since the actions are often used in succession (e.g., shuffle the tree color until it's good). so, it can probably stay as is. however, for the context menu on the group item, the behavior is different (it will close directly after using the entry).
• when using this action on a tree which is invisible, it will be turned visible, but all the other trees won't turn invisible. maybe acceptable, since one can just click again. can be reproduced with this state of trees:

[hotzenklotz]

@philippotto Updated the changeling :-)

the context menu does not close when using the new item. it's a bit weird, but in line with most of the other items, since the actions are often used in succession (e.g., shuffle the tree color until it's good). so, it can probably stay as is. however, for the context menu on the group item, the behavior is different (it will close directly after using the entry).

Good catch. I fixed this. Now the context menu closes after clicking on the "Hide/Show" menu entry.

when using this action on a tree which is invisible, it will be turned visible, but all the other trees won't turn invisible. maybe acceptable, since one can just click again. can be reproduced with this state of trees:

Yes, this is odd. But since I am relying on an existing functionality I will not changes that as part of this PR.

[philippotto]

Good stuff!