Add SenderActionModel

src/Infrastructure/BotSharp.Abstraction/Messaging/Models/RichContent/SenderActionModel.cs

@@ -0,0 +1,15 @@
+
+namespace BotSharp.Abstraction.Messaging.Models.RichContent
+{
+    public class SenderActionModel
+    {
+        /* 
+         * Requests to display sender action should only include the sender_action parameter and the recipient object.
+         * All other Send API properties, such as text and templates, should be sent in a separate request.
+        */
+        public Recipient Recipient { get; set; } = new Recipient();
+
+        [JsonPropertyName("sender_action")]
+        public string SenderAction { get; set; } = string.Empty;
+    }
+}