arrow key navigation widgets don't work well with NVDA

[WofWca]

• Operating System (Linux/Mac/Windows/iOS/Android): Windows
• Delta Chat Version: 1.50.1
• Expected behavior: Focus switches to the next chat list item, as would happen if NVDA was not active, as designed in improvement: arrow-key navigation for chat list #4224.
• Actual behavior: NVDA announces an item inside the next chat list item, and document.activeElement doesn't change. Pressing ArrowDown again makes NVDA announce the next item within the same chat list item.
• Steps to reproduce the problem:
  1. Launch NVDA.
  2. Open Delta Chat.
  3. Tab-navigate to an item in the list of chats.
  4. Press ArrowDown.
• Screenshots:
• Logs:

As I stated in #4294, we probably need to utilize role="listbox" or role="application" or similar. Adding role="application" on the items wrapper solves the problem that this issue describes, but I am not sure whether this is correct otherwise.
A good resource would be https://www.w3.org/WAI/ARIA/apg/patterns/listbox/ or https://www.w3.org/WAI/ARIA/apg/patterns/grid/.