Changes for devnet-8 (#4518)

* Addressed #4487

Add override threshold flag
Added tests for Override Threshold Flag
Override default shown in decimal

* Addressed #4445

Addressed Jimmy's Comments
No need for matches
Fix Mock Execution Engine Tests
Fix clippy
fix fcuv3 bug

* Fix Block Root Calculation post-Deneb

* Addressed #4444

Attestation Verification Post-Deneb
Fix Gossip Attestation Verification Test

* Addressed #4443

Fix Exit Signing for EIP-7044
Fix cross exit test
Move 7044 Logic to signing_context()

* Update EF Tests

* Addressed #4560

* Added Comments around EIP7045

* Combine Altair Deneb to Eliminate Duplicated Code

beacon_node/operation_pool/src/lib.rs

@@ -1852,7 +1852,21 @@ mod release_tests {
         // Sign an exit with the Altair domain and a phase0 epoch. This is a weird type of exit
         // that is valid because after the Bellatrix fork we'll use the Altair fork domain to verify
         // all prior epochs.
-        let exit2 = harness.make_voluntary_exit(2, Epoch::new(0));
+        let unsigned_exit = VoluntaryExit {
+            epoch: Epoch::new(0),
+            validator_index: 2,
+        };
+        let exit2 = SignedVoluntaryExit {
+            message: unsigned_exit.clone(),
+            signature: harness.validator_keypairs[2]
+                .sk
+                .sign(unsigned_exit.signing_root(spec.compute_domain(
+                    Domain::VoluntaryExit,
+                    harness.spec.altair_fork_version,
+                    harness.chain.genesis_validators_root,
+                ))),
+        };
+
         let verified_exit2 = exit2
             .clone()
             .validate(&bellatrix_head.beacon_state, &harness.chain.spec)