Adding the ReaderInterface

* A new Class `\Bakame\Csv\Reader` is introduced to ease CSV data reading.

* The  `\Bakame\Csv\Codec::loadString`,  `\Bakame\Csv\Codec::`loadFile`,  `\Bakame\Csv\Codec::`save` methods now return a `\Bakame\Csv\Reader` object

* The Csv Controls Setters and Getters are now in a Traits to be used by the Reader and the Codec class to remove duplicate code