Fixed a ton of state_processing stuff (#3642)

FIXME's:
 * consensus/fork_choice/src/fork_choice.rs
 * consensus/state_processing/src/per_epoch_processing/capella.rs
 * consensus/types/src/execution_payload_header.rs
 
TODO's:
 * consensus/state_processing/src/per_epoch_processing/capella/partial_withdrawals.rs
 * consensus/state_processing/src/per_epoch_processing/capella/full_withdrawals.rs

consensus/state_processing/src/per_block_processing/process_operations.rs

@@ -232,6 +232,7 @@ pub fn process_attestations<'a, T: EthSpec, Payload: AbstractExecPayload<T>>(
         }
         BeaconBlockBodyRef::Altair(_)
         | BeaconBlockBodyRef::Merge(_)
+        | BeaconBlockBodyRef::Capella(_)
         | BeaconBlockBodyRef::Eip4844(_) => {
             altair::process_attestations(
                 state,

consensus/state_processing/src/per_block_processing/signature_sets.rs

@@ -8,7 +8,7 @@ use std::borrow::Cow;
 use tree_hash::TreeHash;
 use types::{
     AbstractExecPayload, AggregateSignature, AttesterSlashing, BeaconBlockRef, BeaconState,
-    BeaconStateError, ChainSpec, DepositData, Domain, Epoch, EthSpec, ExecPayload, Fork, Hash256,
+    BeaconStateError, ChainSpec, DepositData, Domain, Epoch, EthSpec, Fork, Hash256,
     InconsistentFork, IndexedAttestation, ProposerSlashing, PublicKey, PublicKeyBytes, Signature,
     SignedAggregateAndProof, SignedBeaconBlock, SignedBeaconBlockHeader,
     SignedContributionAndProof, SignedRoot, SignedVoluntaryExit, SigningData, Slot, SyncAggregate,