Dark mode, stall notification
- Added a notification in the client if the client-server connection exceeds the timout because of a bad connection or high server load
- 3rd party: Updated to Flatlaf 1.1 (https://www.formdev.com/flatlaf/) which added the following main features in dark mode: Embedded dialogs have dark title bars now
and menues of embedded frames are embedded in the title bar now - Added additional instructions to the documentation about the required PostgreSQL database user rights