Added shortcut to collapse sidebar (#8157)

Author: oleklukasiewicz

src/Files/Views/MainPage.xaml

@@ -205,6 +205,16 @@
                 </icore:EventTriggerBehavior>
             </i:Interaction.Behaviors>
         </KeyboardAccelerator>
+        <KeyboardAccelerator
+            Key="S" 
+            x:Name="ToggleSidebarVisibilityKeyboardAcceleretor"
+            Modifiers="Control,Menu">
+            <i:Interaction.Behaviors>
+                <icore:EventTriggerBehavior EventName="Invoked">
+                    <icore:InvokeCommandAction Command="{x:Bind ToggleSidebarCollapsedStateCommand}"/>
+                </icore:EventTriggerBehavior>
+            </i:Interaction.Behaviors>
+        </KeyboardAccelerator>
     </Page.KeyboardAccelerators>
 
     <controls:SidebarControl

src/Files/Views/MainPage.xaml.cs

@@ -48,6 +48,8 @@ public MainPageViewModel ViewModel
         private ICommand ToggleCompactOverlayCommand { get; }
         private ICommand SetCompactOverlayCommand { get; }
 
+        private ICommand ToggleSidebarCollapsedStateCommand => new RelayCommand<KeyboardAcceleratorInvokedEventArgs>(x => ToggleSidebarCollapsedState(x));
+       
         public bool IsVerticalTabFlyoutEnabled => UserSettingsService.MultitaskingSettingsService.IsVerticalTabFlyoutEnabled;
 
         public MainPage()
@@ -355,6 +357,13 @@ private void ToggleFullScreenAccelerator(KeyboardAcceleratorInvokedEventArgs e)
             e.Handled = true;
         }
 
+        private void ToggleSidebarCollapsedState(KeyboardAcceleratorInvokedEventArgs e)
+        {
+            SidebarAdaptiveViewModel.IsSidebarOpen = !SidebarAdaptiveViewModel.IsSidebarOpen;
+
+            e.Handled=true;
+        }
+
         private void SidebarControl_Loaded(object sender, RoutedEventArgs e)
         {
             SidebarAdaptiveViewModel.UpdateTabControlMargin(); // Set the correct tab margin on startup