Add finalized to HTTP API responses (#3753)

## Issue Addressed

#3708 

## Proposed Changes
- Add `is_finalized_block` method to `BeaconChain` in `beacon_node/beacon_chain/src/beacon_chain.rs`.
- Add `is_finalized_state` method to `BeaconChain` in `beacon_node/beacon_chain/src/beacon_chain.rs`.
- Add `fork_and_execution_optimistic_and_finalized` in `beacon_node/http_api/src/state_id.rs`.
- Add `ExecutionOptimisticFinalizedForkVersionedResponse` type in `consensus/types/src/fork_versioned_response.rs`.
- Add `execution_optimistic_finalized_fork_versioned_response`function in  `beacon_node/http_api/src/version.rs`.
- Add `ExecutionOptimisticFinalizedResponse` type in `common/eth2/src/types.rs`.
- Add `add_execution_optimistic_finalized` method in  `common/eth2/src/types.rs`.
- Update API response methods to include finalized.
- Remove `execution_optimistic_fork_versioned_response`

Co-authored-by: Michael Sproul <michael@sigmaprime.io>

beacon_node/store/src/hot_cold_store.rs

@@ -1741,7 +1741,7 @@ fn no_state_root_iter() -> Option<std::iter::Empty<Result<(Hash256, Slot), Error
 /// Allows full reconstruction by replaying blocks.
 #[derive(Debug, Clone, Copy, Default, Encode, Decode)]
 pub struct HotStateSummary {
-    slot: Slot,
+    pub slot: Slot,
     pub latest_block_root: Hash256,
     epoch_boundary_state_root: Hash256,
 }