Switched to enforced deserialisation order

Created by: DreamingRaven

Please see the relevant commits for more details, but the order of setstate has been enforced as it cannot be guaranteed what order the dictionary keys will end up in, once they go through validation using marshmallow. This causes problems such as encryption parameters being loaded later than ciphertext, which obviously cannot happen as seal.load requires both the ciphertext file and the context (generated by parameters)