Improve room member list UX:
- Don't display the list in chunks anymore.
- Use an indeterminate linear progress indicator to display some loading is being done (either loading the cached list or the updated one).
- Try to make sure we don't display the members loaded from timeline items as the cached room list by mistake.
* Update screenshots
* Simplify member loading logic.
---------
Co-authored-by: ElementBot <benoitm+elementbot@element.io>
1670909408