Final changes for fusaka-devnet-2 (#7655)

Closes #7467.

This PR primarily addresses [the P2P changes](https://github.com/ethereum/EIPs/pull/9840) in [fusaka-devnet-2](https://fusaka-devnet-2.ethpandaops.io/). Specifically:

* [the new `nfd` parameter added to the `ENR`](https://github.com/ethereum/EIPs/pull/9840)
* [the modified `compute_fork_digest()` changes for every BPO fork](https://github.com/ethereum/EIPs/pull/9840)

90% of this PR was absolutely hacked together as fast as possible during the Berlinterop as fast as I could while running between Glamsterdam debates. Luckily, it seems to work. But I was unable to be as careful in avoiding bugs as I usually am. I've cleaned up the things *I remember* wanting to come back and have a closer look at. But still working on this.

Progress:
* [x] get it working on `fusaka-devnet-2`
* [ ] [*optional* disconnect from peers with incorrect `nfd` at the fork boundary](https://github.com/ethereum/consensus-specs/pull/4407) - Can be addressed in a future PR if necessary
* [x] first pass clean-up
* [x] fix up all the broken tests
* [x] final self-review
* [x] more thorough review from people more familiar with affected code

lcli/src/generate_bootnode_enr.rs

@@ -32,12 +32,13 @@ pub fn run<E: EthSpec>(matches: &ArgMatches, spec: &ChainSpec) -> Result<(), Str
 
     let secp256k1_keypair = secp256k1::Keypair::generate();
     let enr_key = CombinedKey::from_secp256k1(&secp256k1_keypair);
+    let genesis_fork_digest = spec.compute_fork_digest(Hash256::zero(), Epoch::new(0));
     let enr_fork_id = EnrForkId {
-        fork_digest: ChainSpec::compute_fork_digest(genesis_fork_version, Hash256::zero()),
+        fork_digest: genesis_fork_digest,
         next_fork_version: genesis_fork_version,
         next_fork_epoch: Epoch::max_value(), // FAR_FUTURE_EPOCH
     };
-    let enr = build_enr::<E>(&enr_key, &config, &enr_fork_id, spec)
+    let enr = build_enr::<E>(&enr_key, &config, &enr_fork_id, genesis_fork_digest, spec)
         .map_err(|e| format!("Unable to create ENR: {:?}", e))?;
 
     fs::create_dir_all(&output_dir).map_err(|e| format!("Unable to create output-dir: {:?}", e))?;