chore(chainspec): Add trait `ConfigureHardforks`

[emhane]

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Ref https://github.com/paradigmxyz/reth/issues/10468

Conversion from alloy_genesis::Genesis to reth_chainspec::ChainSpec has optimism feature gates on code related to hard forks. This PR moves closer to enabling the implementation From<Genesis> for ChainSpec<H>, where ChainSpec is generic over hard fork.