[fxcop] Settings UI library (part 2) (#7257)

* Suppress warnings for read-only collection properties (see code comments)

* Call ConfigureAwait on tasks

* Add CultureInfo and StringComparison policy for certain string operations

* Add checks and exceptions for null arguments to public methods

* Rename RaisePropertyChanged to NotifyPropertyChanged

* Suppress CA1000 warning on SettingsRepository class

* Implement Disposable pattern in HotkeySettingsControlHook

* Modify null argument handling in KeyboardManagerViewModel::CombineShortcutLists

src/core/Microsoft.PowerToys.Settings.UI.Lib/CustomAction/SendCustomAction.cs

@@ -25,7 +25,8 @@ namespace Microsoft.PowerToys.Settings.UI.Lib.CustomAction
             {
                 PropertyNamingPolicy = new CustomNamePolicy((propertyName) =>
                 {
-                    return propertyName.Equals("ModuleAction") ? moduleName : propertyName;
+                    // Using Ordinal as this is an internal property name
+                    return propertyName.Equals("ModuleAction", System.StringComparison.Ordinal) ? moduleName : propertyName;
                 }),
             };