Remove CountUnrealized (#4357)

## Issue Addressed

Closes #4332

## Proposed Changes

Remove the `CountUnrealized` type, defaulting unrealized justification to _on_. This fixes the #4332 issue by ensuring that importing the same block to fork choice always results in the same outcome.

Finalized sync speed may be slightly impacted by this change, but that is deemed an acceptable trade-off until the optimisation from #4118 is implemented.

TODO:

- [x] Also check that the block isn't a duplicate before importing

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -63,7 +63,6 @@ use execution_layer::{
     BlockProposalContents, BuilderParams, ChainHealth, ExecutionLayer, FailedCondition,
     PayloadAttributes, PayloadStatus,
 };
-pub use fork_choice::CountUnrealized;
 use fork_choice::{
     AttestationFromBlock, ExecutionStatus, ForkChoice, ForkchoiceUpdateParameters,
     InvalidationOperation, PayloadVerificationStatus, ResetPayloadStatuses,
@@ -2510,7 +2509,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
     pub async fn process_chain_segment(
         self: &Arc<Self>,
         chain_segment: Vec<Arc<SignedBeaconBlock<T::EthSpec>>>,
-        count_unrealized: CountUnrealized,
         notify_execution_layer: NotifyExecutionLayer,
     ) -> ChainSegmentResult<T::EthSpec> {
         let mut imported_blocks = 0;
@@ -2579,7 +2577,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                     .process_block(
                         signature_verified_block.block_root(),
                         signature_verified_block,
-                        count_unrealized,
                         notify_execution_layer,
                     )
                     .await
@@ -2668,7 +2665,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         self: &Arc<Self>,
         block_root: Hash256,
         unverified_block: B,
-        count_unrealized: CountUnrealized,
         notify_execution_layer: NotifyExecutionLayer,
     ) -> Result<Hash256, BlockError<T::EthSpec>> {
         // Start the Prometheus timer.
@@ -2689,7 +2685,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 notify_execution_layer,
             )?;
             chain
-                .import_execution_pending_block(execution_pending, count_unrealized)
+                .import_execution_pending_block(execution_pending)
                 .await
         };
 
@@ -2744,10 +2740,9 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
     ///
     /// An error is returned if the block was unable to be imported. It may be partially imported
     /// (i.e., this function is not atomic).
-    async fn import_execution_pending_block(
+    pub async fn import_execution_pending_block(
         self: Arc<Self>,
         execution_pending_block: ExecutionPendingBlock<T>,
-        count_unrealized: CountUnrealized,
     ) -> Result<Hash256, BlockError<T::EthSpec>> {
         let ExecutionPendingBlock {
             block,
@@ -2808,7 +2803,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                         state,
                         confirmed_state_roots,
                         payload_verification_status,
-                        count_unrealized,
                         parent_block,
                         parent_eth1_finalization_data,
                         consensus_context,
@@ -2834,7 +2828,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         mut state: BeaconState<T::EthSpec>,
         confirmed_state_roots: Vec<Hash256>,
         payload_verification_status: PayloadVerificationStatus,
-        count_unrealized: CountUnrealized,
         parent_block: SignedBlindedBeaconBlock<T::EthSpec>,
         parent_eth1_finalization_data: Eth1FinalizationData,
         mut consensus_context: ConsensusContext<T::EthSpec>,
@@ -2903,7 +2896,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                     &state,
                     payload_verification_status,
                     &self.spec,
-                    count_unrealized,
                 )
                 .map_err(|e| BlockError::BeaconChainError(e.into()))?;
         }