Remove consensus/types re-exports (#8540)

There are certain crates which we re-export within `types` which creates a fragmented DevEx, where there are various ways to import the same crates.

```rust
// consensus/types/src/lib.rs
pub use bls::{
AggregatePublicKey, AggregateSignature, Error as BlsError, Keypair, PUBLIC_KEY_BYTES_LEN,
PublicKey, PublicKeyBytes, SIGNATURE_BYTES_LEN, SecretKey, Signature, SignatureBytes,
get_withdrawal_credentials,
};
pub use context_deserialize::{ContextDeserialize, context_deserialize};
pub use fixed_bytes::FixedBytesExtended;
pub use milhouse::{self, List, Vector};
pub use ssz_types::{BitList, BitVector, FixedVector, VariableList, typenum, typenum::Unsigned};
pub use superstruct::superstruct;
```

This PR removes these re-exports and makes it explicit that these types are imported from a non-`consensus/types` crate.


Co-Authored-By: Mac L <mjladson@pm.me>

beacon_node/beacon_chain/src/sync_committee_verification.rs

@@ -30,6 +30,7 @@ use crate::observed_attesters::SlotSubcommitteeIndex;
 use crate::{
     BeaconChain, BeaconChainError, BeaconChainTypes, metrics, observed_aggregates::ObserveOutcome,
 };
+use bls::AggregateSignature;
 use bls::{PublicKeyBytes, verify_signature_sets};
 use educe::Educe;
 use safe_arith::ArithError;
@@ -51,7 +52,7 @@ use types::consts::altair::SYNC_COMMITTEE_SUBNET_COUNT;
 use types::slot_data::SlotData;
 use types::sync_committee::SyncCommitteeError;
 use types::{
-    AggregateSignature, BeaconStateError, EthSpec, Hash256, SignedContributionAndProof, Slot,
+    BeaconStateError, EthSpec, Hash256, SignedContributionAndProof, Slot,
     SyncCommitteeContribution, SyncCommitteeMessage, SyncSelectionProof, SyncSubnetId,
     sync_committee_contribution::Error as ContributionError,
 };