Ui for sbt-server

### Sub tasks

- Stream api ✔
- layout and widgets ✔
    - plugin layout
    - header
    - navigation and status shortcuts
    - panels
- home
- adapt tutorials
- build/compile
- code/editor
- run/inspect
    - full logs
    - actors
    - requests
    - deviations
- test
- monitor

Each bullet point should be a PR
There was a reason we didn't initialize until visible, though annoyingly commit 66d77eed992022f4800ea61463629044b9d6fdf4 does not explain what it was. I think it was because Chrome may have loaded the javascript but not the DOM or didn't do any layout or something, when you opened a tab in the background? Will that regress with this removal?