[ MenuBar ] In high contrast, the focus visual overlaps the button bo…

…rder and is barely (or not at all) visible (#6730)

* date pickers

* adding time picker and flyout theming

* update background smoke for hc

* fixing focus and high contrast outline on menu bar item

dev/MenuBar/MenuBarItem.xaml

@@ -16,6 +16,7 @@
         <Setter Property="IsTabStop" Value="True"/>
         <Setter Property="ExitDisplayModeOnAccessKeyInvoked" Value="False"/>
         <Setter Property="UseSystemFocusVisuals" Value="True"/>
+        <Setter Property="FocusVisualMargin" Value="-3"/>
         <Setter Property="Template">
             <Setter.Value>
                 <ControlTemplate TargetType="local:MenuBarItem">
@@ -69,6 +70,8 @@
 
                         <Border x:Name="Background"
                             Background="{TemplateBinding Background}"
+                            contract7Present:CornerRadius="{TemplateBinding CornerRadius}"
+                            contract7NotPresent:CornerRadius="{ThemeResource ControlCornerRadius}"
                             BorderThickness="{TemplateBinding BorderThickness}"
                             BorderBrush="{TemplateBinding BorderBrush}"/>