feat: async header transform

[frisitano]

Overview

Previously, the map method on the HeaderTransform trait was synchronous. To work around this constraint in the rollup-node we would spawn a new background task to insert the signatures into the database. However, this resulted in an unbounded number of tokio tasks responsible for inserting singatures into the database being spawned. In this PR we make the map method async and await the result of the map method before we send the result to the client. This provides a natural backpressure on the system.

[codspeed-hq]

CodSpeed Performance Report

Merging #365 will not alter performance

_{Comparing feat/async-header-transform (09b2e43) with scroll (797d440)}

Summary

✅ 77 untouched

[yiweichi]

LGTM, I wonder do we have issue caused by this on sepolia/mainnet now? like a oom? or some block missing its signature on db?

[frisitano]

LGTM, I wonder do we have issue caused by this on sepolia/mainnet now? like a oom? or some block missing its signature on db?

No, this is only a problem when we sync from genesis. Please also review the rollup-node PR to see how they work together scroll-tech/rollup-node#427.