Sync fixes (#801)

* Randomize peer selection for batch errors

* Downgrade attestation logging

* Handle range sync errors

* Update lock file

* Downgrade logs

* Decrease batch size for better thread handling

* Optimise peer selection in range sync

beacon_node/network/src/sync/range_sync/mod.rs

@@ -1,6 +1,7 @@
 //! This provides the logic for syncing a chain when the local node is far behind it's current
 //! peers.
 
+mod batch;
 mod chain;
 mod chain_collection;
 mod range;