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/http_api/src/standard_block_rewards.rs

@@ -10,8 +10,8 @@ use warp_utils::reject::beacon_chain_error;
 pub fn compute_beacon_block_rewards<T: BeaconChainTypes>(
     chain: Arc<BeaconChain<T>>,
     block_id: BlockId,
-) -> Result<(StandardBlockReward, ExecutionOptimistic), warp::Rejection> {
-    let (block, execution_optimistic) = block_id.blinded_block(&chain)?;
+) -> Result<(StandardBlockReward, ExecutionOptimistic, bool), warp::Rejection> {
+    let (block, execution_optimistic, finalized) = block_id.blinded_block(&chain)?;
 
     let block_ref = block.message();
 
@@ -23,5 +23,5 @@ pub fn compute_beacon_block_rewards<T: BeaconChainTypes>(
         .compute_beacon_block_reward(block_ref, block_root, &mut state)
         .map_err(beacon_chain_error)?;
 
-    Ok((rewards, execution_optimistic))
+    Ok((rewards, execution_optimistic, finalized))
 }