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>

slasher/src/attester_record.rs

@@ -1,5 +1,7 @@
 use crate::{Error, database::IndexedAttestationId};
+use bls::AggregateSignature;
 use ssz_derive::{Decode, Encode};
+use ssz_types::VariableList;
 use std::borrow::Cow;
 use std::sync::{
     Arc,
@@ -7,7 +9,7 @@ use std::sync::{
 };
 use tree_hash::TreeHash as _;
 use tree_hash_derive::TreeHash;
-use types::{AggregateSignature, EthSpec, Hash256, IndexedAttestation, VariableList};
+use types::{EthSpec, Hash256, IndexedAttestation};
 
 #[derive(Debug, Clone, Copy)]
 pub struct AttesterRecord {