* Refactor `Attestation` production
* Add constant
* Start refactor for aggregation
* Return early when no attesting validators
* Refactor into individual functions
* Tidy, add comments
* Add first draft of NaiveAggregationPool
* Further progress on naive aggregation pool
* Fix compile errors in VC
* Change locking logic for naive pool
* Introduce AttesationType
* Add pruning, comments
* Add MAX_ATTESTATIONS_PER_SLOT restriction
* Add pruning based on slot
* Update BN for new aggregation fns
* Fix test compile errors
* Fix failing rest_api test
* Move SignedAggregateAndProof into own file
* Update docs, fix warning
* Tidy some formatting in validator API
* Remove T::default_spec from signing
* Fix failing rest test
* Tidy
* Add test, fix bug
* Improve naive pool tests
* Add max attestations test
* Revert changes to the op_pool
* Refactor timer
