Added PowerPoint templates to the Slide Assistant (#1055)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Tools/PowerPoint/SlidePicture.cs

@@ -0,0 +1,11 @@
+namespace AIStudio.Tools.PowerPoint;
+
+/// <summary>
+/// A picture, ready to be placed on a slide.
+/// </summary>
+/// <param name="Data">The encoded image.</param>
+/// <param name="ContentType">The MIME type of the encoded image, e.g., "image/png".</param>
+/// <param name="Width">The width in pixels.</param>
+/// <param name="Height">The height in pixels.</param>
+/// <param name="IsIcon">Whether the picture is an icon of a picture library, which is never cropped.</param>
+internal sealed record SlidePicture(byte[] Data, string ContentType, int Width, int Height, bool IsIcon = false);