nbxmpp does not support client certificates anymore

- Add info back to tooltips
- Remove info from ChatControls
- Issue events via contacts

- Move GroupchatInfo Page into Dialog
- Refactor handling muc subject

This restores the window correctly again

- Don’t load user status history
- Use UserStatus row for displaying

- Feature is broken since mid 2020
- No demand since then to fix it

- Move methods from gui_interface
- Add NoneBackend for Wayland
- Further simplify code