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.

common/eth2/Cargo.toml

@@ -13,15 +13,15 @@ types = { path = "../../consensus/types" }
 reqwest = { version = "0.11.0", features = ["json","stream"] }
 lighthouse_network = { path = "../../beacon_node/lighthouse_network" }
 proto_array = { path = "../../consensus/proto_array", optional = true }
-eth2_serde_utils = "0.1.1"
+ethereum_serde_utils = "0.5.0"
 eth2_keystore = { path = "../../crypto/eth2_keystore" }
 libsecp256k1 = "0.7.0"
 ring = "0.16.19"
 bytes = "1.0.1"
 account_utils = { path = "../../common/account_utils" }
 sensitive_url = { path = "../../common/sensitive_url" }
-eth2_ssz = "0.4.1"
-eth2_ssz_derive = "0.3.1"
+ethereum_ssz = "0.5.0"
+ethereum_ssz_derive = "0.5.0"
 futures-util = "0.3.8"
 futures = "0.3.8"
 store = { path = "../../beacon_node/store", optional = true }