Split common crates out into their own repos (#3890)

## Proposed Changes

Split out several crates which now exist in separate repos under `sigp`.

- [`ssz` and `ssz_derive`](https://github.com/sigp/ethereum_ssz)
- [`tree_hash` and `tree_hash_derive`](https://github.com/sigp/tree_hash)
- [`ethereum_hashing`](https://github.com/sigp/ethereum_hashing)
- [`ethereum_serde_utils`](https://github.com/sigp/ethereum_serde_utils)
- [`ssz_types`](https://github.com/sigp/ssz_types)

For the published crates see: https://crates.io/teams/github:sigp:crates-io?sort=recent-updates.

## Additional Info

- [x] Need to work out how to handle versioning. I was hoping to do 1.0 versions of several crates, but if they depend on `ethereum-types 0.x` that is not going to work. EDIT: decided to go with 0.5.x versions.
- [x] Need to port several changes from `tree-states`, `capella`, `eip4844` branches to the external repos.

beacon_node/beacon_chain/src/builder.rs

@@ -999,7 +999,7 @@ fn descriptive_db_error(item: &str, error: &StoreError) -> String {
 mod test {
     use super::*;
     use crate::validator_monitor::DEFAULT_INDIVIDUAL_TRACKING_THRESHOLD;
-    use eth2_hashing::hash;
+    use ethereum_hashing::hash;
     use genesis::{
         generate_deterministic_keypairs, interop_genesis_state, DEFAULT_ETH1_BLOCK_HASH,
     };

beacon_node/beacon_chain/src/eth1_chain.rs

@@ -1,7 +1,7 @@
 use crate::metrics;
 use eth1::{Config as Eth1Config, Eth1Block, Service as HttpService};
 use eth2::lighthouse::Eth1SyncStatusData;
-use eth2_hashing::hash;
+use ethereum_hashing::hash;
 use int_to_bytes::int_to_bytes32;
 use slog::{debug, error, trace, Logger};
 use ssz::{Decode, Encode};