feat: respect OffScreenMargin for elements in chrome layer.

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

@@ -64,6 +64,7 @@
                     <Panel Margin="{TemplateBinding WindowDecorationMargin}" Background="Transparent" />
                     <VisualLayerManager Padding="{TemplateBinding OffScreenMargin, Mode=OneWay}">
                         <VisualLayerManager.ChromeOverlayLayer>
+                            <Panel Margin="{Binding $parent[u:UrsaWindow].OffScreenMargin}">
                                 <u:TitleBar
                                     Margin="{Binding $parent[u:UrsaWindow].TitleBarMargin}"
                                     Content="{Binding $parent[u:UrsaWindow].TitleBarContent}"
@@ -79,6 +80,7 @@
                                             IsVisible="{Binding $parent[u:UrsaWindow].IsManagedResizerVisible}" />
                                     </Panel>
                                 </VisualLayerManager>
+                            </Panel>
                         </VisualLayerManager.ChromeOverlayLayer>
                         <Panel>
                             <ContentPresenter