Fix conversation_end

Author: Oceania2018

src/Infrastructure/BotSharp.Core/Conversations/Services/ConversationService.SendMessage.cs

@@ -150,6 +150,7 @@ await hook.OnTaskCompleted(response)
                 await HookEmitter.Emit<IConversationHook>(_services, async hook =>
                     await hook.OnConversationEnding(response)
                 );
+                response.FunctionName = "conversation_end";
             }
         }
 

src/Infrastructure/BotSharp.Core/Routing/Handlers/RouteToAgentRoutingHandler.cs

@@ -26,6 +26,10 @@ public class RouteToAgentRoutingHandler : RoutingHandlerBase, IRoutingHandler
         new ParameterPropertyDef("user_goal_agent",
             "agent who can acheive user initial task,  must align with user_goal_description.", 
             required: true),
+        new ParameterPropertyDef("conversation_end",
+            "user is ending the conversation.",
+            type: "boolean",
+            required: true),
         new ParameterPropertyDef("is_new_task",
             "whether the user is requesting a new task that is different from the previous topic.", 
             type: "boolean")