htr is fast now, so hitting the database to load the state root is no
longer motivated - the more simple code is less vulnerable to database
corruption.
* update most of the remaining non-fork-choice spec refs, updating code where necessary
* revert presumably harmless compute_signing_root() change, but this way, keep things really unchanged outside inspector
* cleanups
* fix ncli state root check flag
* add block dump to ncli_db
* limit ncli_db benchmark length
* tone down finalization logs
* introduce trusted blocks
We only store blocks whose signature we've verified in the database - as
such, there's no need to check it again, and most importantly, no need
to deserialize the signature when loading from database.
50x startup time improvement, 200x block load time improvement.
* fix rewinding when deposits have invalid signature
* speed up ancestor iteration by avoiding copy
* avoid deserializing signatures for trusted data
* load blocks lazily when rewinding (less memory used)
* chronicles workarounds
* document trustedbeaconblock