Synchronize list focus with active segment

[dieknolle3333]

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• create a lot of segments so that one can scroll in the segments view
• click on a segment in the data viewport and ensure that the segments view scrolls and highlights to the corresponding item

TODOs:

• create context menu entry
• fix issue that only available segments are stored as selected (e.g. after deleting a segment, see commented-out-code). test this by removing a selected segment
• highlight difference between jump to segment and Select segment in viewport segment dropdown
• make sure the "click segment" action from context menu doesnt harm anything
• actually focus segment in list, so scroll to it via this.tree.current.scrollTo({ key: selectedElement.key }); with the key being segment-<id>
  • fix that scrolling doesnt work for newly added segments
    -> may be bug
• fix drag and drop in segment list, e.g. to groups (seperate issue: Support drag and drop of multiple segments #7527)
• remove logging and read through the rest of the code

Issues:

• fixes Segment list focus is not in sync with active segment #7311

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

• Updated changelog
• Considered common edge cases

[dieknolle3333]

@philippotto I decided that a multiselection of segment should not be overwritten by a click on a segment. Because both the context menu entry and the segment click are causing the same action, the context menu entry doesnt overwrite it either. Thats probably counterintuitive. Obviously I could build around that, but I just wanted to make sure that we are keeping both ways to focus the segment :) So we are keeping the context menu entry and the click, right? Or should I ask for more opinions first?

[dieknolle3333]

there may be edge cases where this context menu entry is displayed although it doesnt make sense, but I think that applies for more than this context menu entry. see #7538. I didnt know what edge exactly I found, but if its easy I will of course fix it in this PR :)

[philippotto]

great stuff :) I left some feedback, but overall it's already looking pretty good 👍

[philippotto]

Works great for me :)