Decouple beacon-node and state-transition

[twoeths]

Problem description

right now beacon-node and state-transition both stay on typescript
in the near future, beacon-node stays on typescript while state transition is siwtched to native (zig) in lodestar-z
so we need to prepare for that

Solution description

avoid having CachedBeaconStateAllForks in all function parameters of beacon node. Instead of that, we need to implement a light version of BeaconState, for example

export interface IBeaconStateView {
  slot: Slot;
  root: Bytes32;
  rootHex: RootHex;
  epoch: Epoch;
  genesisTime: number;
  latestExecutionPayloadBlockHash: Bytes32;
  previousDecisionRoot: RootHex;
  currentDecisionRoot: RootHex;
  nextDecisionRoot: RootHex;
  effectiveBalanceIncrements: Uint16Array;
  previousJustifiedCheckpoint: Checkpoint;
  currentJustifiedCheckpoint: Checkpoint;
  finalizedCheckpoint: Checkpoint;
  getRandaoMix(epoch: Epoch): Bytes32;
  getProposerIndex(slot: Slot): number;
  getBlockRootAtSlot(slot: Slot): Root;
  getValidator(index: number): phase0.Validator;
}

• for now, in each consumer flow we create an implementation of IBeaconStateView, for example TSBeaconStateView, based on an existing CachedBeaconStateAllForks and pass it everywhere
• once it's done we populate TSBeaconStateView to state cache, changes all interface of regen + state cache to IBeaconStateView
• once we have a binding for lodestar-z, we'll have another implementation, for example NativeBeaconStateView to lazy load and cache above data from native, then populate regen + state cache with it. All consumer codes of state cache + regen are unchanged because they work with IBeaconStateView
• this provides way to have a feature flag to switch it on and off. Once it's stable we'll turn it on by default, like what we did in worker thread

also need to avoid using EpochCache data/functions

Tracked issues

• Avoid accessing config, pubkey2index, index2pubkey from cached state #8652
• Avoid accessing full beacon state in PrepareNextSlotScheduler #8651
• Refactor ShufflingCache #8653
• Remove Eth1ForBlockProduction #8654
• Use ShufflingCache instead of EpochCache for shuffling data #8655
• Gossip validation to work with EpochShuffling #8657
• Produce block using parent IBeaconStateView #8658
• Regen and state caches to work with IBeaconStateView #8659
• Api to work with IBeaconStateView #8663

[philknows]

Rough gantt chart of some of our goals. Subject to change as timelines are estimated.