Test settings editor

[roblourens]

• AnyOS @sandy081
• AnyOS @auchenberg

Test #51773

Use the settings editor and the table of contents.

• The selected setting, or setting at the top of the viewport, should be synced to the TOC and its group should be highlighted
• You can tab through UI elements in a sane way, use arrow keys to navigate inside the trees, and press enter to edit the selected setting
• The way settings are divided into categories seems useful and reasonable

And please just file issues for any other oddity you notice or opinion you have, especially about the way the table of contents works.

Complexity: 3