perf(engine): pre-warm in-memory database by executing all transactions in parallel

[rkrasiuk]

Description

Execute all transactions in parallel (perhaps if tx len or gas used exceeds certain threshold) to pre-warm in-memory state. Then execute the block with pre-warmed state.

reth/crates/engine/tree/src/tree/mod.rs

Lines 2174 to 2180 in 2fba3c0

	let block_number = block.number;
	let block_hash = block.hash();
	let sealed_block = Arc::new(block.block.clone());
	let block = block.unseal();
	let exec_time = Instant::now();
	let output = self.metrics.executor.execute_metered(executor, (&block, U256::MAX).into())?;

Additional Context

Related to #11161 as it will allow us to start gathering proofs