Add Fulu boilerplate (#6695)

* Add Fulu boilerplate

* Add more boilerplate

* Change fulu_time to osaka_time

* Merge branch 'unstable' into fulu-boilerplate

* Fix tests

* Merge branch 'unstable' into fulu-boilerplate

* More test fixes

* Apply suggestions

* Remove `get_payload` boilerplate

* Add lightclient fulu types and fix beacon-chain-tests

* Disable Fulu in ef-tests

* Reduce boilerplate for future forks

* Small fixes

* One more fix

* Apply suggestions

* Merge branch 'unstable' into fulu-boilerplate

* Fix lints

validator_client/signing_method/src/web3signer.rs

@@ -29,6 +29,7 @@ pub enum ForkName {
     Capella,
     Deneb,
     Electra,
+    Fulu,
 }
 
 #[derive(Debug, PartialEq, Serialize)]
@@ -107,6 +108,11 @@ impl<'a, E: EthSpec, Payload: AbstractExecPayload<E>> Web3SignerObject<'a, E, Pa
                 block: None,
                 block_header: Some(block.block_header()),
             }),
+            BeaconBlock::Fulu(_) => Ok(Web3SignerObject::BeaconBlock {
+                version: ForkName::Fulu,
+                block: None,
+                block_header: Some(block.block_header()),
+            }),
         }
     }