move Windows app to Windows folder, create folder for Web, create simplest web api service

Windows/Azaion.Annotator/DTO/AnnotationClass.cs

@@ -0,0 +1,15 @@
+using System.Windows.Media;
+using Azaion.Annotator.Extensions;
+
+namespace Azaion.Annotator.DTO;
+
+public class AnnotationClass(int id, string name = "")
+{
+    public int Id { get; set; } = id;
+
+    public string Name { get; set; } = name;
+    public Color Color { get; set; } = id.ToColor();
+
+    public int ClassNumber => Id + 1;
+    public SolidColorBrush ColorBrush => new(Color);
+}