Separate OP payload builder in new engine

[emhane]

Describe the feature

Remove optimism feature, either by making payload builder injectable or by copying engine impl to an op crate.

reth/crates/engine/local/src/payload.rs

Lines 48 to 63 in ef033ab

	#[cfg(feature = "optimism")]
	impl<ChainSpec> PayloadAttributesBuilder<op_alloy_rpc_types_engine::OpPayloadAttributes>
	for LocalPayloadAttributesBuilder<ChainSpec>
	where
	ChainSpec: Send + Sync + EthereumHardforks + 'static,
	{
	fn build(&self, timestamp: u64) -> op_alloy_rpc_types_engine::OpPayloadAttributes {
	op_alloy_rpc_types_engine::OpPayloadAttributes {
	payload_attributes: self.build(timestamp),
	transactions: None,
	no_tx_pool: None,
	gas_limit: None,
	eip_1559_params: None,
	}
	}
	}

Additional context

No response

[mattsse]

this feature is fine because this is done for optimism types, but this feature should be called op so that is distinguishable from the problematic one