fix: fix various issues.

* fix CornerRadius of CloseButton.
* add IsVisible to Content of DualBadge.
* remove Geometry & sys:.

src/Ursa.Themes.Semi/Controls/DialogShared.axaml

@@ -9,7 +9,7 @@
     </Design.PreviewWith>
 
     <ControlTheme x:Key="OverlayCloseButton" TargetType="Button">
-        <Setter Property="CornerRadius" Value="6" />
+        <Setter Property="CornerRadius" Value="3" />
         <Setter Property="Height" Value="24" />
         <Setter Property="Width" Value="24" />
         <Setter Property="Padding" Value="4" />

src/Ursa.Themes.Semi/Controls/DualBadge.axaml

@@ -49,6 +49,7 @@
                             Name="{x:Static u:DualBadge.PART_ContentPresenter}"
                             Grid.Column="1"
                             TextElement.FontSize="{TemplateBinding FontSize}"
+                            IsVisible="{TemplateBinding Content,Converter={x:Static ObjectConverters.IsNotNull}}"
                             Foreground="{TemplateBinding Foreground}"
                             Background="{TemplateBinding Background}"
                             Padding="{TemplateBinding Padding}"