node: clean up global interfaces

- Mark `NodeBuffer` as deprecated and create `Buffer`
- Rename global `ErrnoError` to `NodeErrnoError`
- Make external modules dependent on `events.EventEmitter`, not `NodeEventEmitter`
- Rename `ReadableStream` to `NodeReadableStream`
- Rename `WritableStream` to `NodeWritableStream`
- Rename  `ReadWriteStream` to `NodeReadWriteStream`
- Make external modules dependent on `stream.*`, not globals, when possible.