refactor: streamline AssistantConsole and useAssistantConsole for improved clarity and functionality

- Refactored AssistantConsole component to utilize the useAssistantConsole hook, consolidating state management and logic.
- Removed redundant state variables and methods from AssistantConsole, enhancing maintainability.
- Updated message handling to ensure proper scrolling behavior during streaming responses.
- Simplified props and emits in ChatSidebar for cleaner integration with the AssistantConsole.
- Enhanced NormalLayout to properly handle the close event for the AssistantConsole, improving user experience.

Author: Marvin Zhang