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/operation_pool/src/lib.rs

@@ -35,12 +35,12 @@ use state_processing::{SigVerifiedOp, VerifyOperation};
 use std::collections::{HashMap, HashSet, hash_map::Entry};
 use std::marker::PhantomData;
 use std::ptr;
+use typenum::Unsigned;
 use types::{
     AbstractExecPayload, Attestation, AttestationData, AttesterSlashing, BeaconState,
     BeaconStateError, ChainSpec, Epoch, EthSpec, ProposerSlashing, SignedBeaconBlock,
     SignedBlsToExecutionChange, SignedVoluntaryExit, Slot, SyncAggregate,
     SyncCommitteeContribution, Validator, sync_aggregate::Error as SyncAggregateError,
-    typenum::Unsigned,
 };
 
 type SyncContributions<E> = RwLock<HashMap<SyncAggregateId, Vec<SyncCommitteeContribution<E>>>>;
@@ -793,6 +793,8 @@ mod release_tests {
     use beacon_chain::test_utils::{
         BeaconChainHarness, EphemeralHarnessType, RelativeSyncCommittee, test_spec,
     };
+    use bls::Keypair;
+    use fixed_bytes::FixedBytesExtended;
     use maplit::hashset;
     use state_processing::epoch_cache::initialize_epoch_cache;
     use state_processing::{VerifyOperation, common::get_attesting_indices_from_state};