[Database] Download Block Hints

[frisitano]

Overview

Currently, we are embedding block hints in the node binary here. This is a convenient and portable way of distributing this data, however, it introduces the consequence of bloating the binary. Instead, we should consider hosting the data and then downloading it during the seeding migration script. This solution needs to be generic so that it can work for both Mainnet and Sepolia. I've created a trait-based solution #81, which could be a suitable approach.