Allow to use translation_domain in FormMapper fieldDescriptionOptions

This will call this function https://github.com/sonata-project/SonataAdminBundle/blob/master/Admin/BaseFieldDescription.php#L466, so it works even if translation_domain is not specified.
Merge pull request #1682 from EmmanuelVella/patch-11

Allow to specify a translation_domain option in list, show and filter "add" method