feat: add IAnnotationStream interface for annotation stream functionality

src/PepperDash.Essentials.Core/DeviceTypeInterfaces/IAnnotationStream.cs

@@ -0,0 +1,19 @@
+namespace PepperDash.Essentials.Core.DeviceTypeInterfaces;
+
+    /// <summary>
+    /// Defines minimum functionality for a device that can provide an annotation stream.
+    /// </summary>
+    public interface IAnnotationStream
+    {
+        /// <summary>
+        /// Starts the annotation stream.
+        /// </summary>
+        /// <param name="streamIdx">The index of the annotation stream to start.</param>
+        bool StartAnnotationForStream(ushort streamIdx);
+        
+        /// <summary>
+        /// Stops the annotation stream.
+        /// </summary>
+        /// <param name="streamIdx">The index of the annotation stream to stop.</param>
+        bool StopAnnotationForStream(ushort streamIdx);
+    }