feat: optimize generate name length (#924)

api/events/event_handlers/generate_conversation_name_when_first_message_created.py

             # generate conversation name
             try:
                 name = LLMGenerator.generate_conversation_name(app_model.tenant_id, message.query, message.answer)
+
+                if len(name) > 75:
+                    name = name[:75] + '...'
+
                 conversation.name = name
             except:
                 conversation.name = 'New Chat'