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/attester_cache.rs

@@ -10,13 +10,14 @@
 //! and penalties can be computed and the `state.current_justified_checkpoint` can be updated.
 
 use crate::{BeaconChain, BeaconChainError, BeaconChainTypes};
+use fixed_bytes::FixedBytesExtended;
 use parking_lot::RwLock;
 use state_processing::state_advance::{Error as StateAdvanceError, partial_state_advance};
 use std::collections::HashMap;
 use std::ops::Range;
 use types::{
-    BeaconState, BeaconStateError, ChainSpec, Checkpoint, Epoch, EthSpec, FixedBytesExtended,
-    Hash256, RelativeEpoch, Slot,
+    BeaconState, BeaconStateError, ChainSpec, Checkpoint, Epoch, EthSpec, Hash256, RelativeEpoch,
+    Slot,
     attestation::AttestationError,
     beacon_state::{
         compute_committee_index_in_epoch, compute_committee_range_in_epoch, epoch_committee_count,