Added PowerPoint templates to the Slide Assistant (#1055)

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

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

@@ -0,0 +1,9 @@
+namespace AIStudio.Tools.PowerPoint;
+
+/// <summary>
+/// What the user chose for the presentation as a whole, beyond the slides themselves.
+/// </summary>
+/// <param name="VariantLabel">The variant all slides are written in, e.g., "A"; null for the first one of the template.</param>
+/// <param name="FooterText">The text of the footer on every slide whose layout has one; empty for no footer.</param>
+/// <param name="KeepEmptyPicturePlaceholders">Whether a new slide keeps the picture placeholders of its layout which no picture fills, so that the user can insert pictures of their own.</param>
+internal sealed record PresentationWriteOptions(string? VariantLabel, string FooterText, bool KeepEmptyPicturePlaceholders);