In BlockPool, we keep the head state around, so it's trivial to restore
the temporary state there and keep going as if nothing happened.
This solves 3 problems:
* stack space - the state copy on mainnet is huge
* GC scanning - using stack space for state slows down the GC
significantly
* reckless copying - the copy itself takes a long time
In state_sim, we'll do the same and allocate on heap - this helps a
little with GC - without it, the collection of the temporary strings
created with `toHex` while printing the json dominates the trace.
* add another check for inconsistent aggregation and committee length, since ncli_transition bypasses process_attestation(...)/check_attestation(...) and calls almost directly into process_epoch(...)
* bump validator functions to v0.11.1 spec references
* bump some spec references to v0.11.1
* poke
* Add "drop by score" ability to PeerPool.
Add tests.
Fix syncmanager queue to start from most fresh data.
* Fix endless cycle at the end of syncing process.
* reduce stack space usage in process_final_updates(...) to avoid fuzzed segfault in https://github.com/status-im/nim-beacon-chain/issues/921
* document motivation behind manually constructing hash_tree_root of a HistoricalBatch
* fix remaining block pool extended validation issues and re-enable first-block-received and block-signature EV checks; enable Merkle validation in beacon_node in eth2_network_simulation; refactor some Merkle proof generation code outside tests/ as a result
* re-enable Merkle validation skipping, since while it works on make eth2_network_simulation, it has issues with local testnet
* tighten already-seen-block blockpool check; move comment closer to conceptually proximate code; queue up maybe-future-valid-blocks as pending to keep libp2p-synchronous interrupt handling time lower
* revert the cleanups, now in a separate PR
* remove the remaining merkle_minimal cleanup remnants, also moved to other PR
* restore PR to only modifying one file after rebasing
* use signatures as summary to compare block contents
* switch signature comparison to be raw byte-wise to ensure no attempts to deserialize it to valid (or not) BLS signatures first
* fix mainnet finalization and swith eth2_network_simulation to a kind of small-mainnet profile
* Fix slot reference in trace logging
* bump a couple of spec refs from v0.11.0 to v0.11.1
* bump another spec ref to v0.11.1, one more try at Jenkins test vector download CI issue
* fix other slot reference in trace logging and skip past single-block/multi-slot gaps to re-approach from ancestry side by state_transitioning, by requiring exact match on both root hash and slot for fast path
* make more precise the fast path condition
* redo logic to make uniform with BeaconChainDB; fix chronos deprecation warning
* revert not-working replacement of deprecated chronos futures `or`
* switch testnet1 to mainnet
* if we don't have validators, don't consider aggregation work
* if we do have validators, don't aggregate when we're out of sync
* when we do aggregate, use a fresh state, and not one from before
sleeping