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/builder.rs

@@ -21,7 +21,9 @@ use crate::validator_pubkey_cache::ValidatorPubkeyCache;
 use crate::{
     BeaconChain, BeaconChainTypes, BeaconForkChoiceStore, BeaconSnapshot, ServerSentEventHandler,
 };
+use bls::Signature;
 use execution_layer::ExecutionLayer;
+use fixed_bytes::FixedBytesExtended;
 use fork_choice::{ForkChoice, ResetPayloadStatuses};
 use futures::channel::mpsc::Sender;
 use kzg::Kzg;
@@ -43,7 +45,7 @@ use tracing::{debug, error, info};
 use types::data_column_custody_group::CustodyIndex;
 use types::{
     BeaconBlock, BeaconState, BlobSidecarList, ChainSpec, ColumnIndex, DataColumnSidecarList,
-    Epoch, EthSpec, FixedBytesExtended, Hash256, Signature, SignedBeaconBlock, Slot,
+    Epoch, EthSpec, Hash256, SignedBeaconBlock, Slot,
 };
 
 /// An empty struct used to "witness" all the `BeaconChainTypes` traits. It has no user-facing