migrate Pilz.Win32 & optimize Pilz & Pilz.IO

Pilz.Win32/Mapped/SystemIconSize.cs

@@ -0,0 +1,13 @@
+
+namespace Pilz.Win32.Mapped;
+
+
+/// <summary>
+/// Two constants extracted from the FileInfoFlags, the only that are
+/// meaningfull for the user of this class.
+/// </summary>
+public enum SystemIconSize : int
+{
+    Large,
+    Small
+}