Option to toggle the system tray icon (#23220)

* Added option to toggle the system tray icon

At the moment, this hides the icon making the settings window inaccessible without first modifying the general `settings.json` file.

* Use IPC messages to manage the tray icon settings

* Fix launching second window binds to active settings process

* Added context menu option to hide tray icon

* Added Exit PT button to settings ui NavigationView.PaneFooter

* Moved DllImports to NativeMethods.cs

* Sentence case titles

* Fix whitespace

* Re-add exit icon to NavView

* Re-added toggle switch to new UI

* Fix build

* Fix build after merge main

* Fix the string to display

* add shut down buttons

* finish polish

* fix string

* Styling tweaks to titlebar and settingscards

* fix comment

* fix unit test

* fix ut

---------

Co-authored-by: Jaime Bernardo <jaime@janeasystems.com>
Co-authored-by: vanzue <vanzue@outlook.com>
Co-authored-by: Kayla Cinnamon <cinnamon@microsoft.com>
Co-authored-by: Niels Laute <niels.laute@live.nl>

src/settings-ui/Settings.UI.UnitTests/ViewModelTests/General.cs

@@ -224,6 +224,36 @@ namespace ViewModelTests
             viewModel.ThemeIndex = 0;
         }
 
+        [TestMethod]
+        public void IsShowSysTrayIconEnabledByDefaultShouldDisableWhenSuccessful()
+        {
+            // Arrange
+            // Assert
+            Func<string, int> sendMockIPCConfigMSG = msg =>
+            {
+                OutGoingGeneralSettings snd = JsonSerializer.Deserialize<OutGoingGeneralSettings>(msg);
+                Assert.IsFalse(snd.GeneralSettings.ShowSysTrayIcon);
+                return 0;
+            };
+
+            Func<string, int> sendRestartAdminIPCMessage = msg => { return 0; };
+            Func<string, int> sendCheckForUpdatesIPCMessage = msg => { return 0; };
+            GeneralViewModel viewModel = new(
+                settingsRepository: SettingsRepository<GeneralSettings>.GetInstance(mockGeneralSettingsUtils.Object),
+                "GeneralSettings_RunningAsAdminText",
+                "GeneralSettings_RunningAsUserText",
+                false,
+                false,
+                sendMockIPCConfigMSG,
+                sendRestartAdminIPCMessage,
+                sendCheckForUpdatesIPCMessage,
+                GeneralSettingsFileName);
+            Assert.IsTrue(viewModel.ShowSysTrayIcon);
+
+            // Act
+            viewModel.ShowSysTrayIcon = false;
+        }
+
         [TestMethod]
         public void AllModulesAreEnabledByDefault()
         {