Add missed blocks to monitored validators (#4731)

* add missed_block metric

* init missed_block in constructor

* declare beaconproposercache in ValidatorMonitor

* refacto proposer_shuffling_decision_root to use epoch instead of current.epoch

* imple new proposer_shuffling_decision_root in callers

* push missed_blocks

* prune missed_blocks

* only add to hashmap if it's a monitored validator

* remove current_epoch dup + typos

* extract in func

* add prom metrics

* checkpoint is not only epoch but slot as well

* add safeguard if we start a new chain at slot 0

* clean

* remove unnecessary negative value for a slot

* typo in comment

* remove unused current_epoch

* share beacon_proposer_cache between validator_monitor and beacon_chain

* pass Hash256::zero()

* debug objects

* fix loop: lag is at the head

* sed s/get_slot/get_epoch

* fewer calls to cache.get_epoch

* fix typos

* remove cache first call

* export TYPICAL_SLOTS_PER_EPOCH and use it in validator_monitor

* switch to gauge & loop over missed_blocks hashset

* fix subnet_service tests

* remove unused var

* clean + fix nits

* add beacon_proposer_cache + validator_monitor in builder

* fix store_tests

* fix builder tests

* add tests

* add validator monitor set of tests

* clean tests

* nits

* optimise imports

* lint

* typo

* added self.aggregatable

* duplicate proposer_shuffling_decision_root

* remove duplication in passing beacon_proposer_cache

* remove duplication in passing beacon_proposer_cache

* using indices

* fmt

* implement missed blocks total

* nits

* avoid heap allocation

* remove recursion limit

* fix lint

* Fix valdiator monitor builder pattern

Unify validator monitor config struct

* renaming metrics

* renaming metrics in validator monitor

* add log if there's a missing validator index

* consistent log

* fix loop

* better loop

* move gauge to counter

* fmt

* add error message

* lint

* fix prom metrics

* set gauge to 0 when non-finalized epochs

* better wording

* remove hash256::zero in favour of block_root

* fix gauge total label

* fix last missed block validator

* Add `MissedBlock` struct

* Fix comment

* Refactor non-finalized block loop

* Fix off-by-one

* Avoid string allocation

* Fix compile error

* Remove non-finalized blocks metric

* fix func clojure

* remove unused variable

* remove unused DEFAULT_INDIVIDUAL_TRACKING_THRESHOLD

* remove unused DEFAULT_INDIVIDUAL_TRACKING_THRESHOLD in builder

* add validator index depending on the fork name

* typos

---------

Co-authored-by: Paul Hauner <paul@paulhauner.com>

beacon_node/network/src/subnet_service/tests/mod.rs

@@ -2,7 +2,6 @@ use super::*;
 use beacon_chain::{
     builder::{BeaconChainBuilder, Witness},
     eth1_chain::CachingEth1Backend,
-    validator_monitor::DEFAULT_INDIVIDUAL_TRACKING_THRESHOLD,
     BeaconChain,
 };
 use futures::prelude::*;
@@ -76,7 +75,6 @@ impl TestBeaconChain {
                     Duration::from_millis(SLOT_DURATION_MILLIS),
                 ))
                 .shutdown_sender(shutdown_tx)
-                .monitor_validators(true, vec![], DEFAULT_INDIVIDUAL_TRACKING_THRESHOLD, log)
                 .build()
                 .expect("should build"),
         );