feat: add action

Author: giancarloromeo

services/web/server/src/simcore_service_webserver/conversations/_conversation_message_service.py

@@ -38,6 +38,7 @@ def _make_project_conversation_message_created_message(
     return SocketMessageDict(
         event_type=SOCKET_IO_PROJECT_CONVERSATION_MESSAGE_CREATED_EVENT,
         data={
+            "action": "create",
             "project_id": project_id,
             **conversation_message.model_dump(mode="json"),
         },