Chardonnay UI bug fixes and improvements

- Theme changes do not require restart
- Fix some text appearing black in dark mode
- Fix dialog boxes not appearing correctly on Windows
- Fix queue vertical scroll bar overlapping items

Source/LibationAvalonia/Controls/Settings/Important.axaml

@@ -166,16 +166,7 @@
 				MinWidth="80"
 				SelectedItem="{CompiledBinding ThemeVariant, Mode=TwoWay}"
 				ItemsSource="{CompiledBinding Themes}"/>
-
-			<TextBlock
-				Grid.Column="2"
-				FontSize="16"
-				FontWeight="Bold"
-				Margin="10,0"
-				VerticalAlignment="Center"
-				IsVisible="{CompiledBinding	SelectionChanged}"
-				Text="Theme change takes effect on restart"/>
-
+			
 		</Grid>
 	</Grid>
 </UserControl>