[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/RemapKeysDataModel.cs

@@ -17,4 +17,4 @@ namespace Microsoft.PowerToys.Settings.UI.Lib
             InProcessRemapKeys = new List<KeysDataModel>();
         }
     }
-}
+}