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));
     }
 }

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

@@ -1,13 +1,16 @@
-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;
 using System.Windows.Input;
 
 namespace Microsoft.PowerToys.Settings.UI.Helpers
 {
     public class RelayCommand : ICommand
     {
-        private readonly Action execute;
-
-        private readonly Func<bool> canExecute;
+        private readonly Action _execute;
+        private readonly Func<bool> _canExecute;
 
         public event EventHandler CanExecuteChanged;
 
@@ -18,17 +21,18 @@ namespace Microsoft.PowerToys.Settings.UI.Helpers
 
         public RelayCommand(Action execute, Func<bool> canExecute)
         {
-            this.execute = execute ?? throw new ArgumentNullException(nameof(execute));
-            this.canExecute = canExecute;
+            _execute = execute ?? throw new ArgumentNullException(nameof(execute));
+            _canExecute = canExecute;
         }
 
-        public bool CanExecute(object parameter) => this.canExecute == null || this.canExecute();
+        public bool CanExecute(object parameter) => _canExecute == null || _canExecute();
 
-        public void Execute(object parameter) => this.execute();
+        public void Execute(object parameter) => _execute();
 
-        public void OnCanExecuteChanged() => this.CanExecuteChanged?.Invoke(this, EventArgs.Empty);
+        public void OnCanExecuteChanged() => CanExecuteChanged?.Invoke(this, EventArgs.Empty);
     }
 
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("StyleCop.CSharp.MaintainabilityRules", "SA1402:File may only contain a single type", Justification = "abstract T and abstract")]
     public class RelayCommand<T> : ICommand
     {
         private readonly Action<T> execute;
@@ -48,10 +52,10 @@ namespace Microsoft.PowerToys.Settings.UI.Helpers
             this.canExecute = canExecute;
         }
 
-        public bool CanExecute(object parameter) => this.canExecute == null || this.canExecute((T)parameter);
+        public bool CanExecute(object parameter) => canExecute == null || canExecute((T)parameter);
 
-        public void Execute(object parameter) => this.execute((T)parameter);
+        public void Execute(object parameter) => execute((T)parameter);
 
-        public void OnCanExecuteChanged() => this.CanExecuteChanged?.Invoke(this, EventArgs.Empty);
+        public void OnCanExecuteChanged() => CanExecuteChanged?.Invoke(this, EventArgs.Empty);
     }
 }

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

@@ -2,9 +2,6 @@
 // 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;
-using System.Runtime.InteropServices;
-
 using Windows.ApplicationModel.Resources;
 
 namespace Microsoft.PowerToys.Settings.UI.Helpers