* Added support for S3 storage classes
* Added missing translations for S3 storage class
* Changed default storage class values to preserve original behaviour
* Changed storage class description and example
* Fix translations ordering
* Change configuration defaults to empty strings
* Remove redundant empty string check
* Validate storage class variable against constants from S3 API docs
* Validate export storage class against constants
* Use slices for config validation
* Applied patch for translation ordering