feat(optimistic_block): Introduce the optimistic block struct #9456

Job	Run time
Backward Compatibility	10m 6s
Database Migration	10m 6s
Cargo Nextest (Linux)	9m 54s
Protobuf Backward Compatibility	12s
Cargo Nextest (Linux Nightly)	10m 7s
Sanity Checks	6m 25s
Cargo Deny	29s
Cargo Fmt	23s
Cargo Clippy	9m 11s
Rust Doctests	10m 6s
Protocol Schema	10m 4s
Genesis Changes	10m 6s
Style	37s
Upgradability	10m 6s
Cargo Audit	20s
Non-default Configuration Builds	1m 15s
Themis	41s
Unused Dependencies	6m 58s
Cargo check publishable packages separately (Linux, linux, ubuntu-latest)	8m 9s
Cargo check publishable packages separately (Windows, win, windows-latest)	1m 59s
Generate Coverage Artifact	1s
Upload Coverage	1s
	1h 57m 16s

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