* Simplify block quarantine blobless
The quarantine blobless table was initially keyed off of (Eth2Digest,
ValidatorSig). This was modelled off the orphan table. The presence of
the signature in the key is necessary for orphans, because we can't
verify the signature for an orphan. That is not the case for a
blobless block, where the signature can be verified.
So this PR changes the blobless block table to be keyed off a
Eth2Digest only. This simplifies the retrieval and handling of
blobless blocks.
* review feedback
* Harden handling of unviable forks
In our current handling of unviable forks, we allow peers to send us
blocks that come from a different fork - this is not necessarily an
error as it can happen naturally, but it does open up the client to a
case where the same unviable fork keeps getting requested - rather than
allowing this to happen, we'll now give these peers a small negative
score - if it keeps happening, we'll disconnect them.
* keep track of unviable forks in quarantine, to avoid filling it with
known junk
* collect peer scores in single module
* descore peers when they send unviable blocks during sync
* don't give score for duplicate blocks
* increase quarantine size to a level that allows finality to happen
under optimal conditions - this helps avoid downloading the same blocks
over and over in case of an unviable fork
* increase initial score for new peers to make room for one more failure
before disconnection
* log and score invalid/unviable blocks in requestmanager too
* avoid ChainDAG dependency in quarantine
* reject gossip blocks with unviable parent
* continue processing unviable sync blocks in order to build unviable
dag
* docs
* Update beacon_chain/consensus_object_pools/block_pools_types.nim
* add unviable queue test