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/store/Cargo.toml

@@ -13,8 +13,8 @@ db-key = "0.0.5"
 leveldb = { version = "0.8.6", default-features = false }
 parking_lot = "0.12.0"
 itertools = "0.10.0"
-eth2_ssz = "0.4.1"
-eth2_ssz_derive = "0.3.1"
+ethereum_ssz = "0.5.0"
+ethereum_ssz_derive = "0.5.0"
 types = { path =  "../../consensus/types" }
 state_processing = { path = "../../consensus/state_processing" }
 slog = "2.5.2"