Response Validation & Processing

- [x] Add Response Precondition checking
- [x] Add Response signature verification
- [x] Add Response Validation
- [X] Add Response Assertion Decryption
- [x] Add Response Assertion Validation
- [x] Add Response Assertion Transformers
- [ ] Test all the things
Awww, not yet (didn't want to create the dependency on Doctrine\Common\Collections) but will add support for it :wink: as well as `last` and `map`. Any other requests?