optimize project structure

src/plugins/arc/data_resource.py

src/plugins/arxiv/handlers.py

src/plugins/ask/__init__.py

src/plugins/ask/ask_utils.py

src/plugins/ask/parse_question.py

src/plugins/avatar/generate.py

src/plugins/calc/__init__.py

src/plugins/help/__init__.py

src/plugins/image/data_resource.py

src/plugins/record/__init__.py

src/plugins/record/grep.py

src/plugins/response/events.py

src/utils/__init__.py

src/utils/message.py

src/utils/recorder.py