[AaruFormat] Add function to retrieve image information from library.

Aaru.Images/AaruFormat/Metadata.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace Aaru.Images;
+
+public sealed partial class AaruFormat
+{
+    // AARU_EXPORT int32_t AARU_CALL aaruf_get_image_info(const void *context, ImageInfo *image_info)
+    [DllImport("libaaruformat",
+               EntryPoint = "aaruf_get_image_info",
+               SetLastError = true,
+               CallingConvention = CallingConvention.StdCall)]
+    private static extern Status aaruf_get_image_info(IntPtr context, ref AaruFormatImageInfo imageInfo);
+}