Tree-sync friendly lookup sync tests (#8592)

- Step 0 of the tree-sync roadmap https://github.com/sigp/lighthouse/issues/7678

Current lookup sync tests are written in an explicit way that assume how the internals of lookup sync work. For example the test would do:

- Emit unknown block parent message
- Expect block request for X
- Respond with successful block request
- Expect block processing request for X
- Response with successful processing request
- etc..

This is unnecessarily verbose. And it will requires a complete re-write when something changes in the internals of lookup sync (has happened a few times, mostly for deneb and fulu).

What we really want to assert is:

- WHEN: we receive an unknown block parent message
- THEN: Lookup sync can sync that block
- ASSERT: Without penalizing peers, without unnecessary retries


  Keep all existing tests and add new cases but written in the new style described above. The logic to serve and respond to request is in this function `fn simulate` 2288a3aeb1/beacon_node/network/src/sync/tests/lookups.rs (L301)
- It controls peer behavior based on a `CompleteStrategy` where you can set for example "respond to BlocksByRoot requests with empty"
- It actually runs beacon processor messages running their clousures. Now sync tests actually import blocks, increasing the test coverage to the interaction of sync and the da_checker.
- To achieve the above the tests create real blocks with the test harness. To make the tests as fast as before, I disabled crypto with `TestConfig`

Along the way I found a couple bugs, which I documented on the diff.


Co-Authored-By: dapplion <35266934+dapplion@users.noreply.github.com>

beacon_node/network/src/sync/manager.rs

@@ -70,6 +70,7 @@ use slot_clock::SlotClock;
 use std::ops::Sub;
 use std::sync::Arc;
 use std::time::Duration;
+use strum::IntoStaticStr;
 use tokio::sync::mpsc;
 use tracing::{debug, error, info, trace};
 use types::{
@@ -90,7 +91,7 @@ pub const SLOT_IMPORT_TOLERANCE: usize = 32;
 /// arbitrary number that covers a full slot, but allows recovery if sync get stuck for a few slots.
 const NOTIFIED_UNKNOWN_ROOT_EXPIRY_SECONDS: u64 = 30;
 
-#[derive(Debug)]
+#[derive(Debug, IntoStaticStr)]
 /// A message that can be sent to the sync manager thread.
 pub enum SyncMessage<E: EthSpec> {
     /// A useful peer has been discovered.
@@ -323,17 +324,18 @@ impl<T: BeaconChainTypes> SyncManager<T> {
     }
 
     #[cfg(test)]
-    pub(crate) fn active_single_lookups(&self) -> Vec<super::block_lookups::BlockLookupSummary> {
-        self.block_lookups.active_single_lookups()
+    pub(crate) fn send_sync_message(&mut self, sync_message: SyncMessage<<T>::EthSpec>) {
+        self.network.send_sync_message(sync_message);
     }
 
     #[cfg(test)]
-    pub(crate) fn active_parent_lookups(&self) -> Vec<Vec<Hash256>> {
-        self.block_lookups
-            .active_parent_lookups()
-            .iter()
-            .map(|c| c.chain.clone())
-            .collect()
+    pub(crate) fn block_lookups(&self) -> &BlockLookups<T> {
+        &self.block_lookups
+    }
+
+    #[cfg(test)]
+    pub(crate) fn range_sync(&self) -> &RangeSync<T> {
+        &self.range_sync
     }
 
     #[cfg(test)]
@@ -512,17 +514,18 @@ impl<T: BeaconChainTypes> SyncManager<T> {
     /// there is no way to guarantee that libp2p always emits a error along with
     /// the disconnect.
     fn peer_disconnect(&mut self, peer_id: &PeerId) {
-        // Inject a Disconnected error on all requests associated with the disconnected peer
-        // to retry all batches/lookups
-        for sync_request_id in self.network.peer_disconnected(peer_id) {
-            self.inject_error(*peer_id, sync_request_id, RPCError::Disconnected);
-        }
-
         // Remove peer from all data structures
         self.range_sync.peer_disconnect(&mut self.network, peer_id);
         let _ = self.backfill_sync.peer_disconnected(peer_id);
         self.block_lookups.peer_disconnected(peer_id);
 
+        // Inject a Disconnected error on all requests associated with the disconnected peer
+        // to retry all batches/lookups. Only after removing the peer from the data structures to
+        // avoid sending retry requests to the disconnecting peer.
+        for sync_request_id in self.network.peer_disconnected(peer_id) {
+            self.inject_error(*peer_id, sync_request_id, RPCError::Disconnected);
+        }
+
         // Regardless of the outcome, we update the sync status.
         self.update_sync_state();
     }