feat: calc block base reward use block number only

[jsvisa]

ref #8868 (comment)

[onbjerg]

i don't think the idea was removing the ttd check entirely, just avoiding fetching ttd where possible by checking with the block number first, e.g. if paris is not activated at a specific block number, we'd need to fetch the ttd and check again because it might be a false negative (in the case where we don't know the number of the merge block)

cc @mattsse for clarification

[jsvisa]

@onbjerg I have the same thoughts as you, but after some consideration, if the chain has passed merge, it must be set paris_block_and_final_difficulty, so I think there's no need to check the ttd again.

[onbjerg]

The block is only set if its present in the chain spec, which is not the case for all chains, e.g. if the block is not known, but the TTD is. We don't update the chain spec while the node is running, so we don't set the block when we detect TTD has been passed.

[mattsse]

we can't safely do that, but what we can do this, add a new function that checks the base block reward pre-merge based on the block number

[jsvisa]

@mattsse ptal, seems the is_paris_active_at_block is missed in #8891, so add back in this pr; and add a simple func base_block_reward_pre_merge returns 2,3,5 ETH for blocks before merge. I'll check if the block is after merge or not in #8868 before invoking base_block_reward, so no need to adjust more in this pr, wdyt.

[mattsse]

-.- adding back in #8896

[mattsse]

nvm, I'll include it here, ty

[mattsse]

lgtm

completed