* Revert "Revert "Upgrade database schema" (#2570)"
This reverts commit 6057c2ffb4.
* ssz: fix loading empty lists into existing instances
Not a problem earlier because we didn't reuse instances
* bump nim-eth
* bump nim-web3
The `kvstore` design we're using now turns out to not be the best way to
use `sqlite` - in particular, there are some significant benefits to
using rowid in certain situations and to keep data in separate tables.
With this branch, there are massive improvements in startup time
(seconds instead of minutes) and state/block storage and pruning times
(milliseconds instead of seconds) - these improvements can in particular
be seen on slow drives and translate directly into better attestation
performance.
* update kvstore to new keyspace design
* remove `DirStoreRef` and the hidden `--state-db-kind` option - this
was an experiment to store large blobs in files, but with the new
kvstore, there's no compelling reason to do so
* remove `DbMap` - unused and would need updating for new keyspace
design
* introduce separate tables for each data type (blocks, states etc)
* remove "WITHOUT ROWID" pessimization for tables with large blobs
* close DbSeq statements explicitly (and earlier)
* store beacon block summaries in separate table, without SSZ
compression and load them all with single query on startup
* stop storing backwards compat full states
* mark genesis beacon block as trusted
* avoid faststreams when loading SSZ data
* remove `DisagreementBehavior` (unused)
Since quite a lot of additional procs were now compiled as generics, this lead to compiler bugs that had
to be worked-around:
* The `Domain` type was renamed to `Eth2Domain` to avoid compilation errors
due to conflicts with `nativesockets.Domain`.
Similarly, `eth2_network.KeyPair` was renamed to `NetKeyPair`.
* A new more robust version of `hexToByteArray` was added to stew
* reorder ssz
* split into hash_trees and ssz_serialization, roughly, for hashing and
IO
* move bitseqs into ssz (from stew)
* clean up imports
* docs, imports