[Keyboard Manager] Add JSON support for App Specific shortcuts (#4840)

* Enable app specific shortcut remapping

* Fixed lowercase function call

* Add test file

* Moved GetForegroundProcess to II and added tests

* Fixed runtime error while testing due to heap allocation across dll boundary

* Renamed function

* Changed shortcutBuffer type

* Linked App specific UI to backend

* Added shortcut validation logic on TextBox LostFocus handler

* Moved Validate function and changed default text

* Changed to case insensitive warning check

* Changed to case insensitive warning check at OnClickAccept

* Fixed alignment and spacing issues

* Added app-specific JSON support in backend

* Updated landing page

* Make listview horizontally scrollable

* Added tests

* Consider all case variants of All Apps in textbox to be global shortcuts

src/core/Microsoft.PowerToys.Settings.UI.Lib/AppSpecificKeysDataModel.cs

@@ -0,0 +1,32 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json.Serialization;
+using Microsoft.PowerToys.Settings.UI.Lib.Utilities;
+
+namespace Microsoft.PowerToys.Settings.UI.Lib
+{
+    public class AppSpecificKeysDataModel : KeysDataModel
+    {
+        [JsonPropertyName("targetApp")]
+        public string TargetApp { get; set; }
+
+        public new List<string> GetOriginalKeys()
+        {
+            return base.GetOriginalKeys();
+        }
+
+        public new List<string> GetNewRemapKeys()
+        {
+            return base.GetNewRemapKeys();
+        }
+
+        public bool Compare(AppSpecificKeysDataModel arg)
+        {
+            return OriginalKeys.Equals(arg.OriginalKeys) && NewRemapKeys.Equals(arg.NewRemapKeys) && TargetApp.Equals(arg.TargetApp);
+        }
+    }
+}