Mining stopped because of endorsement and other fixes

[vsuharnikov]

• Trigger finalization calculations on key block: finalize or not N-2 by votes in N-1 on receiving N
• Rescheduling miner after microblock, min-micro-block-age setting applied only on a local node
• Anyone can challenge a block
• Don't broadcast an endorsement if not enough generating balance
• Don't accept endorsements from poor endorsers
• Fixed sorting of endorsements
• Fixed limit of max valid endorsements
• Liquid block (NG: keyblock and microblocks) has the same signature as a hard block
• New process of private BLS key generation (common with Go-version)
• minimal-block-generation-offset based on previous block timestamp
• Config: max-endorsements renamed to max-valid-endorsers
• Additional tests
• Fixed flaky docker tests
• Remove sbt-docker, build via external process