Fix EZP-21977: Fixed output binary file size display

The units suffixes are configurable and can be changed with: ezpublish.twig.extension.filesize.suffixes .
The bytes factor is 1000 instead of 1024 to be more usual for users.
The internationalization here is mostly used only to choose between point and coma pattern.
Fix EZP-21977: Moved ez_is_field_empty data provider test
the data provider of ez_is_field_empty was not at the right place and that was giving us problems with the tests of our issue.
Fix EZP-21977: Modification of getLocal() method and tests
Merge pull request #646 from StephaneDiot/ezp-21977_binary_file_size

Fix EZP-21977: improve output of binary field filesize