Move all tests that are copied from [react-refresh](https://github.com/facebook/react/blob/main/packages/react-refresh/src/__tests__/ReactFreshBabelPlugin-test.js) to the `react-refresh` directory, and add a README to describe the source of these tests. This way we can better stay in sync with upstream. related: https://github.com/oxc-project/oxc/pull/6884#discussion_r1816888813
var _jsxFileName