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/lighthouse_network/tests/common.rs

@@ -1,4 +1,5 @@
 #![cfg(test)]
+use fixed_bytes::FixedBytesExtended;
 use lighthouse_network::Enr;
 use lighthouse_network::Multiaddr;
 use lighthouse_network::service::Network as LibP2PService;
@@ -9,10 +10,7 @@ use std::sync::Weak;
 use tokio::runtime::Runtime;
 use tracing::{Instrument, debug, error, info_span};
 use tracing_subscriber::EnvFilter;
-use types::{
-    ChainSpec, EnrForkId, Epoch, EthSpec, FixedBytesExtended, ForkContext, ForkName, Hash256,
-    MinimalEthSpec,
-};
+use types::{ChainSpec, EnrForkId, Epoch, EthSpec, ForkContext, ForkName, Hash256, MinimalEthSpec};
 
 type E = MinimalEthSpec;