Do not add them directly to chain, it will be done by the block queue
manager. Close https://github.com/nspcc-dev/neo-go/issues/2923. However,
this commit is not valid without
https://github.com/roman-khimov/dbft/pull/4.
It's the neo-go's duty to initialize consensus after subsequent block
addition; the dBFT itself must wait for the neo-go to complete the block
addition and notify the dBFT, so that it can initialize at 0-th view to
collect the next block.