feat: refactor with typescript

[fengmk2]

BREAKING CHANGE: Drop Node.js < 16.13.0 support

https://github.com/eggjs/egg-core/issues/264

Checklist

• [ ] npm test passes
• [ ] tests and/or benchmarks are included
• [ ] documentation is changed or added
• [ ] commit message follows commit guidelines

Affected core subsystem(s)

Description of change