Fork choice modifications and cleanup (#3962)

## Issue Addressed

NA

## Proposed Changes

- Implements https://github.com/ethereum/consensus-specs/pull/3290/
- Bumps `ef-tests` to [v1.3.0-rc.4](https://github.com/ethereum/consensus-spec-tests/releases/tag/v1.3.0-rc.4).

The `CountRealizedFull` concept has been removed and the `--count-unrealized-full` and `--count-unrealized` BN flags now do nothing but log a `WARN` when used.

## Database Migration Debt

This PR removes the `best_justified_checkpoint` from fork choice. This field is persisted on-disk and the correct way to go about this would be to make a DB migration to remove the field. However, in this PR I've simply stubbed out the value with a junk value. I've taken this approach because if we're going to do a DB migration I'd love to remove the `Option`s around the justified and finalized checkpoints on `ProtoNode` whilst we're at it. Those options were added in #2822 which was included in Lighthouse v2.1.0. The options were only put there to handle the migration and they've been set to `Some` ever since v2.1.0. There's no reason to keep them as options anymore.

I started adding the DB migration to this branch but I started to feel like I was bloating this rather critical PR with nice-to-haves. I've kept the partially-complete migration [over in my repo](https://github.com/paulhauner/lighthouse/tree/fc-pr-18-migration) so we can pick it up after this PR is merged.

testing/ef_tests/src/cases/fork_choice.rs

@@ -45,7 +45,6 @@ pub struct Checks {
     justified_checkpoint: Option<Checkpoint>,
     justified_checkpoint_root: Option<Hash256>,
     finalized_checkpoint: Option<Checkpoint>,
-    best_justified_checkpoint: Option<Checkpoint>,
     u_justified_checkpoint: Option<Checkpoint>,
     u_finalized_checkpoint: Option<Checkpoint>,
     proposer_boost_root: Option<Hash256>,
@@ -229,7 +228,6 @@ impl<E: EthSpec> Case for ForkChoiceTest<E> {
                         justified_checkpoint,
                         justified_checkpoint_root,
                         finalized_checkpoint,
-                        best_justified_checkpoint,
                         u_justified_checkpoint,
                         u_finalized_checkpoint,
                         proposer_boost_root,
@@ -260,11 +258,6 @@ impl<E: EthSpec> Case for ForkChoiceTest<E> {
                         tester.check_finalized_checkpoint(*expected_finalized_checkpoint)?;
                     }
 
-                    if let Some(expected_best_justified_checkpoint) = best_justified_checkpoint {
-                        tester
-                            .check_best_justified_checkpoint(*expected_best_justified_checkpoint)?;
-                    }
-
                     if let Some(expected_u_justified_checkpoint) = u_justified_checkpoint {
                         tester.check_u_justified_checkpoint(*expected_u_justified_checkpoint)?;
                     }
@@ -378,7 +371,7 @@ impl<E: EthSpec> Tester<E> {
             .chain
             .canonical_head
             .fork_choice_write_lock()
-            .update_time(slot, &self.spec)
+            .update_time(slot)
             .unwrap();
     }
 
@@ -388,7 +381,7 @@ impl<E: EthSpec> Tester<E> {
         let result = self.block_on_dangerous(self.harness.chain.process_block(
             block_root,
             block.clone(),
-            CountUnrealized::False,
+            CountUnrealized::True,
             NotifyExecutionLayer::Yes,
         ))?;
         if result.is_ok() != valid {
@@ -448,7 +441,7 @@ impl<E: EthSpec> Tester<E> {
                         &state,
                         PayloadVerificationStatus::Irrelevant,
                         &self.harness.chain.spec,
-                        self.harness.chain.config.count_unrealized.into(),
+                        CountUnrealized::True,
                     );
 
                 if result.is_ok() {
@@ -576,23 +569,6 @@ impl<E: EthSpec> Tester<E> {
         check_equal("finalized_checkpoint", fc_checkpoint, expected_checkpoint)
     }
 
-    pub fn check_best_justified_checkpoint(
-        &self,
-        expected_checkpoint: Checkpoint,
-    ) -> Result<(), Error> {
-        let best_justified_checkpoint = self
-            .harness
-            .chain
-            .canonical_head
-            .fork_choice_read_lock()
-            .best_justified_checkpoint();
-        check_equal(
-            "best_justified_checkpoint",
-            best_justified_checkpoint,
-            expected_checkpoint,
-        )
-    }
-
     pub fn check_u_justified_checkpoint(
         &self,
         expected_checkpoint: Checkpoint,

testing/ef_tests/src/handler.rs

@@ -547,6 +547,11 @@ impl<E: EthSpec + TypeName> Handler for ForkChoiceHandler<E> {
             return false;
         }
 
+        // Tests are no longer generated for the base/phase0 specification.
+        if fork_name == ForkName::Base {
+            return false;
+        }
+
         // These tests check block validity (which may include signatures) and there is no need to
         // run them with fake crypto.
         cfg!(not(feature = "fake_crypto"))