* Move interfaces from github.com/prysmaticlabs/prysm/beacon-chain/state/interface to github.com/prysmaticlabs/prysm/beacon-chain/state
* remove/rename state2
* Return status.Errorf instead of plain errors from gRPC functions
* return plain errors from helper functions
* change errors to lowercase in node
* correct test expectations
* extracted StateFetcher
* StateFetcher tests
* extract beacon state creation option and fix state tests
* add comment to StateFetcher
* register the server
* implement grpc function
* test ToProto
* gRPC function test with mock state fetcher
* reduce visibility of packages
* add missing error assertion
* removed unused code
* overwrite config name
* gzl
* Fix service fields
* rename StateFetcher to Provider
* Update beacon-chain/state/stateV0/state_trie.go
Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>
* adjust code to new v0 interfaces
* interface/struct naming changes
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>