Joffrey JAFFEUX f189c20578
DEV: ensures thread list has finished loading (#21855)
This should fix this failure:

```
Failures:

  1) Thread list in side panel | full page when there are no threads that the user is participating in shows a message
     Failure/Error: measurement = Benchmark.measure { example.run }
       expected to find text "You are not participating in any threads in this channel." in "Community\nEverything\nMy Posts\nMore\nMessages\nInbox\nChannels\nRandom 25\nPersonal chat\nRandom 25\nShowing all messages\nOngoing discussions"
```

The screenshot failure was clearly showing the spinner still being present.
2023-05-31 15:04:34 +02:00
..
2023-05-25 12:34:00 +02:00