feat: add avalonia PathIcon style.

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Styles/CalendarDemo.axaml

@@ -1,6 +1,5 @@
 <UserControl xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              x:Class="HandyControlDemo.UserControl.CalendarDemo">
-    <Calendar Margin="32"
-              SelectionMode="MultipleRange" />
+    <Calendar Margin="32" />
 </UserControl>