Settingsv2 fix warnings (#2076)

* updating a ton of warnings.

* bunch of cleanup

* few smaller ones

* fixed naming

* reversing an oops

* adjusting json to use attribute

* more json properties

src/core/Microsoft.PowerToys.Settings.UI/Helpers/Observable.cs

@@ -1,4 +1,7 @@
-using System;
+// 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.ComponentModel;
 using System.Runtime.CompilerServices;
 
@@ -16,9 +19,9 @@ namespace Microsoft.PowerToys.Settings.UI.Helpers
             }
 
             storage = value;
-            this.OnPropertyChanged(propertyName);
+            OnPropertyChanged(propertyName);
         }
 
-        protected void OnPropertyChanged(string propertyName) => this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        protected void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
     }
 }