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/store/src/iter.rs

@@ -2,9 +2,9 @@ use crate::errors::HandleUnavailable;
 use crate::{Error, HotColdDB, ItemStore};
 use std::borrow::Cow;
 use std::marker::PhantomData;
+use typenum::Unsigned;
 use types::{
     BeaconState, BeaconStateError, BlindedPayload, EthSpec, Hash256, SignedBeaconBlock, Slot,
-    typenum::Unsigned,
 };
 
 /// Implemented for types that have ancestors (e.g., blocks, states) that may be iterated over.
@@ -387,8 +387,8 @@ mod test {
     use crate::{MemoryStore, StoreConfig as Config};
     use beacon_chain::test_utils::BeaconChainHarness;
     use beacon_chain::types::MainnetEthSpec;
+    use fixed_bytes::FixedBytesExtended;
     use std::sync::Arc;
-    use types::FixedBytesExtended;
 
     fn get_state<E: EthSpec>() -> BeaconState<E> {
         let harness = BeaconChainHarness::builder(E::default())