Settings Flyout improvement (#43840)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request
This pull request introduces the new Quick Access feature to PowerToys
by integrating its host process management into the runner and system
tray. The changes add the Quick Access host implementation, update
project and build files to include it, and modify the runner and tray
icon logic to launch and interact with the Quick Access UI.

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## PR Checklist

- [x] Closes: #43694
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issues) -->
- [x] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [x] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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## Detailed Description of the Pull Request / Additional comments
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## Validation Steps Performed

---------

Signed-off-by: Shawn Yuan (from Dev Box) <shuaiyuan@microsoft.com>
Signed-off-by: Shuai Yuan <shuai.yuan.zju@gmail.com>
Co-authored-by: Niels Laute <niels.laute@live.nl>

src/settings-ui/Settings.UI/SettingsXAML/App.xaml.cs

@@ -41,16 +41,14 @@ namespace Microsoft.PowerToys.Settings.UI
             IsUserAdmin,
             ShowOobeWindow,
             ShowScoobeWindow,
-            ShowFlyout,
             ContainsSettingsWindow,
-            ContainsFlyoutPosition,
         }
 
         private const int RequiredArgumentsSetSettingQty = 4;
         private const int RequiredArgumentsSetAdditionalSettingsQty = 4;
         private const int RequiredArgumentsGetSettingQty = 3;
 
-        private const int RequiredArgumentsLaunchedFromRunnerQty = 12;
+        private const int RequiredArgumentsLaunchedFromRunnerQty = 10;
 
         // Create an instance of the  IPC wrapper.
         private static TwoWayPipeMessageIPCManaged ipcmanager;
@@ -63,8 +61,6 @@ namespace Microsoft.PowerToys.Settings.UI
 
         public bool ShowOobe { get; set; }
 
-        public bool ShowFlyout { get; set; }
-
         public bool ShowScoobe { get; set; }
 
         public Type StartupPage { get; set; } = typeof(Views.DashboardPage);
@@ -194,9 +190,7 @@ namespace Microsoft.PowerToys.Settings.UI
             IsUserAnAdmin = cmdArgs[(int)Arguments.IsUserAdmin] == "true";
             ShowOobe = cmdArgs[(int)Arguments.ShowOobeWindow] == "true";
             ShowScoobe = cmdArgs[(int)Arguments.ShowScoobeWindow] == "true";
-            ShowFlyout = cmdArgs[(int)Arguments.ShowFlyout] == "true";
             bool containsSettingsWindow = cmdArgs[(int)Arguments.ContainsSettingsWindow] == "true";
-            bool containsFlyoutPosition = cmdArgs[(int)Arguments.ContainsFlyoutPosition] == "true";
 
             // To keep track of variable arguments
             int currentArgumentIndex = RequiredArgumentsLaunchedFromRunnerQty;
@@ -209,15 +203,6 @@ namespace Microsoft.PowerToys.Settings.UI
                 currentArgumentIndex++;
             }
 
-            int flyout_x = 0;
-            int flyout_y = 0;
-            if (containsFlyoutPosition)
-            {
-                // get the flyout position arguments
-                _ = int.TryParse(cmdArgs[currentArgumentIndex++], out flyout_x);
-                _ = int.TryParse(cmdArgs[currentArgumentIndex++], out flyout_y);
-            }
-
             RunnerHelper.WaitForPowerToysRunner(PowerToysPID, () =>
             {
                 Environment.Exit(0);
@@ -238,7 +223,7 @@ namespace Microsoft.PowerToys.Settings.UI
                 return 0;
             });
 
-            if (!ShowOobe && !ShowScoobe && !ShowFlyout)
+            if (!ShowOobe && !ShowScoobe)
             {
                 settingsWindow = new MainWindow();
                 settingsWindow.Activate();
@@ -278,16 +263,6 @@ namespace Microsoft.PowerToys.Settings.UI
                     WindowHelpers.ForceTopBorder1PixelInsetOnWindows10(WindowNative.GetWindowHandle(settingsWindow));
                     SetOobeWindow(scoobeWindow);
                 }
-                else if (ShowFlyout)
-                {
-                    POINT? p = null;
-                    if (containsFlyoutPosition)
-                    {
-                        p = new POINT(flyout_x, flyout_y);
-                    }
-
-                    ShellPage.OpenFlyoutCallback(p);
-                }
             }
         }
 
@@ -364,7 +339,6 @@ namespace Microsoft.PowerToys.Settings.UI
 
         private static MainWindow settingsWindow;
         private static OobeWindow oobeWindow;
-        private static FlyoutWindow flyoutWindow;
 
         public static void ClearSettingsWindow()
         {
@@ -381,31 +355,16 @@ namespace Microsoft.PowerToys.Settings.UI
             return oobeWindow;
         }
 
-        public static FlyoutWindow GetFlyoutWindow()
-        {
-            return flyoutWindow;
-        }
-
         public static void SetOobeWindow(OobeWindow window)
         {
             oobeWindow = window;
         }
 
-        public static void SetFlyoutWindow(FlyoutWindow window)
-        {
-            flyoutWindow = window;
-        }
-
         public static void ClearOobeWindow()
         {
             oobeWindow = null;
         }
 
-        public static void ClearFlyoutWindow()
-        {
-            flyoutWindow = null;
-        }
-
         public static Type GetPage(string settingWindow)
         {
             switch (settingWindow)