feat: add tray icon for Datashare to replace opened terminal

[pirhoo]

[mvanzalu]

We would like to have "Quit" and "Open Browser" buttons

• [x] Add the lib into the project (Using version 4.1)
• [x] Make a minimalist demo
• [ ] Integrate SystemTray into the project

[pirhoo]

When starting the app with an X server (for instance in the devenv), there is an error in the console:

Exception in thread "main" java.awt.AWTError: Can't connect to X11 window server using ':0' as the value of the DISPLAY variable.                                                             
        at java.desktop/sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)                                                                                                             
        at java.desktop/sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:105)                                                                                                 
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:318)                                                                                                   
        at java.desktop/sun.awt.X11GraphicsEnvironment.initStatic(X11GraphicsEnvironment.java:64)                                                                                             
        at java.desktop/sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:59)                                                                                               
        at java.desktop/sun.awt.PlatformGraphicsInfo.createGE(PlatformGraphicsInfo.java:36)                                                                                                   
        at java.desktop/java.awt.GraphicsEnvironment$LocalGE.createGE(GraphicsEnvironment.java:91)                                                                                            
        at java.desktop/java.awt.GraphicsEnvironment$LocalGE.<clinit>(GraphicsEnvironment.java:82)                                                                                            
        at java.desktop/java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:104)                                                                                
        at java.desktop/sun.awt.X11.XToolkit.<clinit>(XToolkit.java:225)                                                                                                                      
        at java.desktop/sun.awt.PlatformGraphicsInfo.createToolkit(PlatformGraphicsInfo.java:40)                                                                                              
        at java.desktop/java.awt.Toolkit.getDefaultToolkit(Toolkit.java:595)                                                                                                                  
        at java.desktop/java.awt.SystemTray.isSupported(SystemTray.java:213)                                                                                                                  
        at dorkbox.systemTray.SystemTray.get(SystemTray.java:677)                                                                                                                             
        at dorkbox.systemTray.SystemTray.get(SystemTray.java:171)                                                                                                                             
        at org.icij.datashare.tray.DatashareSystemTray.create(DatashareSystemTray.java:35)                                                                                                    
        at org.icij.datashare.Main.main(Main.java:30) 

We should catch this to display something like "Unable to display the system tray icon".