Fix: The tar file should not be unpacked first

Fix: The tar file should not be unpacked when the object is initalized,
but when a file or a folder is requested!
The wrapper for folders and zip archives can now work for tgz archives also

The wrapper for folders and zip archives can now work for tgz archives
also
Fix: added content checks for products, in order to establish the decode qualification!

Fix: added content checks for products, in order to establish the decode
qualification!