plugin(tool): 更新0.4.2

添加企业微信应用号部署方式，支持插件，支持语音图片交互

docs: update README

The max-line-length configuration was increased to 176 in both .flake8 and pyproject.toml files to allow for longer lines of code.

公众号功能优化：支持图片输入、消息加密模式、用户体验优化

- Add support for message encryption in WeChat MP channel.
- Add `wechatmp_aes_key` configuration item to `config.json`.

Add image compression feature to WechatComAppChannel to compress images larger than 10MB before uploading to WeChat server. The compression is done using the `compress_imgfile` function in `utils.py`. The `fsize` function is also added to `utils.py` to calculate the size of a file or buffer.