feat: allow standard `Request` in `NextAuthHandler` (#4704)
* chore: upgrade dev dependencies
* chore: use SWC for test transforms
* feat: allow standard `Request` as `NextAuthHandler` argument
* test: add initial core tests
* chore: ignore `tests` in build
* chore: fix lint
* chore: move `lib` to `utils`
* add body parsing, simplify
* fix tests
* chore: use `NPM_TOKEN_PKG` for experimental release
