* de-normalize attestationDataRootsBucket to improve performace in CheckAttesterDoubleVotes
* parallize processing of every attestation
* fix double vote test case to take care of jumbled double votes due to parallel processing
* remove attestationRecordsBucket totally and take care of pruning
* missed out build file
* fix review comments
Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>