Added accessible tray icons with:
- dark mode support on Windows and Linux, kudos to @burgosz for the PoC
- template icon support on MacOS
Also added appropriate connecting status icons
This PR updates the system tray icons to reflect both connection status and availability of updates. Now, the tray will show distinct icons for the following states: connected, disconnected, update available while connected, and update available while disconnected. This change improves user experience by providing a clear visual status indicator.
- Add new icons for connected and disconnected states with update available.
- Implement logic to switch icons based on connection status and update availability.
- Remove old icon references for default and update states.
