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/runner/tray_icon.h

@@ -4,6 +4,8 @@
 
 // Start the Tray Icon
 void start_tray_icon(bool isProcessElevated);
+// Change the Tray Icon visibility
+void set_tray_icon_visible(bool shouldIconBeVisible);
 // Stop the Tray Icon
 void stop_tray_icon();
 // Open the Settings Window
@@ -13,4 +15,5 @@ typedef void (*main_loop_callback_function)(PVOID);
 // Calls a callback in _callback
 bool dispatch_run_on_main_ui_thread(main_loop_callback_function _callback, PVOID data);
 
+// Must be the same as: settings-ui/Settings.UI/Views/ShellPage.xaml.cs -> ExitPTItem_Tapped() -> const string ptTrayIconWindowClass
 const inline wchar_t* pt_tray_icon_window_class = L"PToyTrayIconWindow";