perf: arc block submission to avoid redundant clones

[efbig]

📝 Summary

Refactor block submission types to put the main block data in an Arc. Get rid of the redundant deep cloning of block request in the hot relay submission loop here:

rbuilder/crates/rbuilder/src/live_builder/block_output/relay_submit.rs

Lines 454 to 461 in 4ee212e

	let mut request = request.clone();
	// We only set adjustment data on non optimistic v3 submissions.
	// For optimistic v3, it is already included in the header submission.
	if let Some(adjustment_data) = maybe_adjustment_data.filter(|_| optimistic_v3.is_none()) {
	request.set_adjustment_data(adjustment_data.clone().into_v1());
	}

✅ I have completed the following steps:

• Run make lint
• Run make test
• Added tests (if applicable)