* prysm-4757 remove proto.Clone() in favor of existing getters.Copy* methods
* prysm-4757 added a bunch of copy methods, and broke some tests
* squash commits
fix tests and getter implementations
remove usage of CopySignedBeaconBlock from ReceiveBlockNoVerify
* correctly copy Deposit proof and remove proto.clone() again
* Merge branch 'master' into prysm-4757-no-proto-clone
* Merge branch 'master' into prysm-4757-no-proto-clone
* Fix for comments, inline possible function calls
* Merge branch 'master' of https://github.com/prysmaticlabs/Prysm into prysm-4757-no-proto-clone
* Merge branch 'master' into prysm-4757-no-proto-clone
* updated with feedback from review
* Merge branch 'master' into prysm-4757-no-proto-clone
* Merge branch 'master' into prysm-4757-no-proto-clone
* Merge branch 'master' into prysm-4757-no-proto-clone
* Don't save nil head state
* Update head
* Don't update head on new att
* Handle initial sync state in DB can be nil
* Don't update head if it's nil
* Merge branch 'master' of git+ssh://github.com/prysmaticlabs/prysm into handle-init-sync-cache-state
* Merge refs/heads/master into handle-init-sync-cache-state
* Update beacon-chain/blockchain/head.go