Deneb PR feedback updates (#4716)

* move length update outside of if let in LRU cache

* add comment and use hex for G1_POINT_AT_INFINITY

* remove some misleading comments from `ssz_snappy`

* make sure we can't overflow on blobs by range requests with large counts

* downgrade gossip verification internal availability check error

* change blob rpc responses from BlockingFnWithManualSendOnIdle to BlockingFn

* remove unnecessary collect in blobs by range response

* add a comment to blobs by range response start slot logic

* typo persist_data_availabilty_checker -> persist_data_availability_checker

* unify cheap_state_advance_to_obtain_committees

beacon_node/beacon_chain/src/data_availability_checker/overflow_lru_cache.rs

@@ -691,9 +691,9 @@ impl<T: BeaconChainTypes> OverflowLRUCache<T> {
                     // it is still LRU entry -> delete it from memory & record that it's on disk
                     write_lock.in_memory.pop_entry(&lru_root);
                     write_lock.store_keys.insert(lru_root);
-                    stored = write_lock.in_memory.len();
                 }
             }
+            stored = write_lock.in_memory.len();
             drop(write_lock);
         }