* Remove signature verification in backing.
`SignedFullStatement` now signals that the signature has already been
checked.
* Remove unused check_payload function.
* Introduced unchecked signed variants.
* Fix inclusion to use unchecked variant.
* More unchecked variants.
* Use unchecked variants in protocols.
* Start fixing statement-distribution.
* Fixup statement distribution.
* Fix inclusion.
* Fix warning.
* Fix backing properly.
* Fix bitfield distribution.
* Make crypto store optional for `RuntimeInfo`.
* Factor out utility functions.
* get_group_rotation_info
* WIP: Collator cleanup + check signatures.
* Convenience signature checking functions.
* Check signature on collator-side.
* Fix warnings.
* Fix collator side tests.
* Get rid of warnings.
* Better Signed/UncheckedSigned implementation.
Also get rid of Encode/Decode for Signed! *party*
* Get rid of dead code.
* Move Signed in its own module.
* into_checked -> try_into_checked
* Fix merge.
Shawn Tabrizi