Fix ibft not mining bug when network split on waiting for commit mess…

[DarianShawn]

Description

Jury IBFT consensus would not restore to mining in some network split use cases.

Suppose, proposer received enough prepare messages from other nodes, locked the validate state, and missed enough commit message, then the round change. The magic happen, the whole network would not mine at all. The only way to fix is to restart the whole network validator nodes, which is unacceptable.

This PR would fixed it, since we unlock the validate state when a new round change happen, then new propose could be handled properly.

By the way, we add IBFT message validation in validate state, which could prevent some faulty node attacks.

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

[abrahamcruise321]

OK