Added PowerPoint templates to the Slide Assistant (#1055)

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

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

@@ -0,0 +1,27 @@
+namespace AIStudio.Tools.PowerPoint;
+
+/// <summary>
+/// Layouts which offer the same slots at the same places and differ only in their look.
+/// </summary>
+/// <remarks>
+/// Corporate templates often carry every layout in several colors. The model chooses what goes on a
+/// slide, never its color: it sees one entry per family, and the color is chosen for the whole
+/// presentation. Since all variants share the slots, slot n of one variant is slot n of every other
+/// one.
+/// </remarks>
+/// <param name="Id">The short ID the model uses to name the family, e.g., "L3".</param>
+/// <param name="Name">The name the layouts share, e.g., "Inhalt/Content 1".</param>
+/// <param name="Variants">The variants, in the order of the template; never empty.</param>
+internal sealed record LayoutFamily(string Id, string Name, IReadOnlyList<LayoutVariant> Variants)
+{
+    /// <summary>
+    /// The slots every variant of the family offers.
+    /// </summary>
+    public IReadOnlyList<TemplateSlot> Slots => this.Variants[0].Layout.Slots;
+
+    /// <summary>
+    /// The layout of the given variant, or the first one when the family has no such variant.
+    /// </summary>
+    /// <param name="variantLabel">The label of the variant, e.g., "B".</param>
+    public TemplateLayout GetLayout(string? variantLabel) => (this.Variants.FirstOrDefault(variant => variant.Label == variantLabel) ?? this.Variants[0]).Layout;
+}