This function extracts an iterator pointer that can be used to iterate over the key value pairs stored in this table.
Memory Concerns: The iterator pointer passed in must not have non-destroyed iterators assigned to them. The caller, in future must call am_map_entry_iter_destroy to destroy the iterator instance.
If the entry_iter_ptr argument is non-NULL, then the location that it refers to will be set to NULL if an error is returned.