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

scripts/tests/checkpoint-sync-config-devnet.yaml

@@ -3,18 +3,18 @@ participants:
   - cl_type: lighthouse
     cl_image: lighthouse:local
     el_type: geth
-    el_image: ethpandaops/geth:fusaka-devnet-1
+    el_image: ethpandaops/geth:fusaka-devnet-2
     supernode: true
   - cl_type: lighthouse
     cl_image: lighthouse:local
     el_type: geth
-    el_image: ethpandaops/geth:fusaka-devnet-1
+    el_image: ethpandaops/geth:fusaka-devnet-2
     supernode: false
 
 checkpoint_sync_enabled: true
-checkpoint_sync_url: "https://checkpoint-sync.fusaka-devnet-1.ethpandaops.io"
+checkpoint_sync_url: "https://checkpoint-sync.fusaka-devnet-2.ethpandaops.io"
 
 global_log_level: debug
 
 network_params:
-  network: fusaka-devnet-1
+  network: fusaka-devnet-2