fix: Keep voting block if possible

[dima74]

Description

Implements idea from #4518 (comment):

Maybe we can be smarter about when to reject incoming block? Like checking signatures, height, hashes this checks doesn’t need ability to modify state.

This is relatively small change which I think will keep voting block in most cases (however not in all).

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Alternative approach might be to change our state block to accumulate changes localy and take write lock just before applying changes. However it will require large refactoring and might affect performance.

Linked issue

Closes #4643

Benefits

Checklist

• I've read CONTRIBUTING.md
• I've used the standard signed-off commit format (or will squash just before merging)
• All applicable CI checks pass (or I promised to make them pass later)
• (optional) I've written unit tests for the code changes
• I replied to all comments after code review, marking all implemented changes with thumbs up