--test --watch should report the file that triggered the restart

When this PR merge https://github.com/nodejs/node/pull/63781#pullrequestreview-4444888412, Now on Node.js node --watch command, the file that triggered the restart in terminal response

it would also be good now on should be trigger info in test:watch:restarted event ?

we must check these things:
test:watch:restartedcommand public a reporter event, consuming custom report, we if added data is an api change

so should be add document and test doc/api/test.md

any feedback welcome

首先查看 PR 63781 和现有的 test:watch:restarted reporter 事件，然后阅读 doc/api/test.md 中关于其公共 API 的文档。确认公开触发重启的文件是否属于 API 变更，添加相应的测试和文档，并验证该事件会报告重启来源。