Display access key in ToggleButton, ToggleSwitch.

samples/ControlCatalog/Pages/ToggleSwitchPage.xaml

@@ -14,7 +14,7 @@
 
     <Border Classes="Thin">
       <StackPanel>
-        <ToggleSwitch Content="headered" IsChecked="true" Margin="10"/>
+        <ToggleSwitch Content="h_eadered" IsChecked="true" Margin="10"/>
         <TextBox Classes="CodeBox"
           Text="&lt;ToggleSwitch&gt;headered&lt;/ToggleSwitch&gt;"/>
       </StackPanel>
@@ -24,7 +24,7 @@
 
     <Border Classes="Thin">
       <StackPanel>
-        <ToggleSwitch Content="Custom"
+        <ToggleSwitch Content="_Custom"
           OnContent="On"
           OffContent="Off"
           Margin="10"/>
@@ -40,7 +40,7 @@ ContentOff=&quot;Off&quot; /&gt;"
 
     <Border Classes="Thin">
       <StackPanel>
-        <ToggleSwitch Content="Just Click!" Margin="10">
+        <ToggleSwitch Content="_Just Click!" Margin="10">
           <ToggleSwitch.OnContent>
             <Image Source="/Assets/hirsch-899118_640.jpg" Height="32"/>
           </ToggleSwitch.OnContent>

src/Avalonia.Themes.Default/ToggleButton.xaml

@@ -17,6 +17,7 @@
                           ContentTemplate="{TemplateBinding ContentTemplate}"
                           Content="{TemplateBinding Content}"
                           Padding="{TemplateBinding Padding}"
+                          RecognizesAccessKey="True"
                           TextBlock.Foreground="{TemplateBinding Foreground}"
                           HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                           VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>

src/Avalonia.Themes.Default/ToggleSwitch.xaml

@@ -87,6 +87,7 @@
             Grid.Row="0"
             Content="{TemplateBinding Content}"
             ContentTemplate="{TemplateBinding ContentTemplate}"
+            RecognizesAccessKey="True"
             VerticalAlignment="Top"/>
 
           <Grid Grid.Row="1"

src/Avalonia.Themes.Fluent/Controls/ToggleButton.xaml

@@ -34,6 +34,7 @@
                           Content="{TemplateBinding Content}"
                           ContentTemplate="{TemplateBinding ContentTemplate}"
                           Padding="{TemplateBinding Padding}"
+                          RecognizesAccessKey="True"
                           HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                           VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" />
       </ControlTemplate>

src/Avalonia.Themes.Fluent/Controls/ToggleSwitch.xaml

@@ -53,6 +53,7 @@
             Grid.Row="0"
             Content="{TemplateBinding Content}"
             ContentTemplate="{TemplateBinding ContentTemplate}"
+            RecognizesAccessKey="True"
             VerticalAlignment="Top"/>
 
           <Grid Grid.Row="1"