Add php line formatter

Documentation : [see](https://github.com/nicodmf/DatatablesBundle/blob/2ea2f9e1c69bd9278ffbd87912a297848a20a3e0/Resources/doc/lineFormatter.md)

 - change "transformer" to "formatter" in all method, function and parameters to have an uniform naming convention.
 - change the callable to be compatible with old php version.