GODT-1820: hide app windows and tray icon before initating app shutdown.

internal/frontend/bridge-gui/bridge-gui/qml/Bridge.qml

@@ -89,6 +89,8 @@ QtObject {
         }
 
         onQuit: {
+            mainWindow.hide()
+            trayIcon.visible = false
             Backend.quit()
         }
 

internal/frontend/bridge-gui/bridge-gui/qml/StatusWindow.qml

@@ -295,8 +295,8 @@ Window {
                             colorScheme: root.colorScheme
                             text: qsTr("Quit Bridge")
                             onClicked: {
-                                root.quit()
                                 root.close()
+                                root.quit()
                             }
                         }