This PR extends the `nimbus import` command to also allow reading from
era files - this command allows creating or topping up an existing
database with data coming from era files instead of network sync.
* add `--era1-dir` and `--max-blocks` options to command line
* make `persistBlocks` report basic stats like transactions and gas
* improve error reporting in several API
* allow importing multiple RLP files in one go
* clean up logging options to match nimbus-eth2
* make sure database is closed properly on shutdown
- The fluffy test vector repo got forked (well, copied rather) to
become the official one under ethereum github org, so we change
to that repo now and archive ours.
- Our repo also stored accumulator / historical_roots, replace
that with a new repo which is only for network configs.
- Several changes needed to be made due to test vectors that got
updated + some of them got changed to / are yaml format instead of
json.
Jacek Sieka
Jordan Hrycaj
Kim De Mey
jangko