chore: specify genesis block via env

[vietanhduong]

Currently, the genesis block fixed with 0, but there are some chains, the genesis block start from 1.

This PR support specify the genesis block by GRAPH_ETHEREUM_GENESIS_BLOCK_NUMBER, default value is 0.

Related Issue: #3648

[leoyvens]

Hi, @vietanhduong, thank you for the patch, have you verified that this patch allows graph node to successfully sync subgraphs on those chains?

[vietanhduong]

I have just tested with velas chain, and it's works. The unit test failed seem related to these codes on main branch already failed.

I have run tests on my branch, and everything is fine.

[lutter]

I fear a proper fix for this will require quite a bit more work: the genesis block should really be specified in graph-node.toml for each chain, and needs to also be persisted in the database so it's accessible in other places; I assume there's also quite a few places where we implicitly assume that the number of the genesis block is 0 which we'd need to find and update.

[vietanhduong]

@lutter I understand what you consider, but for almost case, the genesis block will start with 0. If there is some problem with the genesis block is start with 1, I think a PR to fix these problems are necessary.