* Add G307 sample code.
The sample should reflect a defered close that leads to data loss.
Due to IDE auto-complete people tend at least log errors, but not
really care about handling.
* Add more G307 sample code. Propose a way to implement
* Remove unused code. Add example that should not return an error but does
* Remove test for synced closed file for now.
Will add this later
Co-authored-by: Cosmin Cojocar <cosmin.cojocar@gmx.ch>