this function copies all entries of a StringNode inside a new one. The new StringNode will result sorted and the internal array rappresentation is recreated in case that the original StringNode has these attributes set.
The new StringNode object must be freed with afc_stringnode_delete() like any other StringNode object.
The new StringNode will contain copies of all string stored, not just references, so it is perfectly safe to afc_stringnode_delete() the original StringNode.
In case the original StringNode had the internal array rappresentation of the list, it will be reproduced in the new StringNode.