Replace DynEthApiBuilder with a trait

[mattsse]

Describe the feature

we currently use

reth/crates/rpc/rpc-builder/src/eth.rs

Lines 11 to 13 in bf44c97

	/// Alias for `eth` namespace API builder.
	pub type DynEthApiBuilder<Provider, Pool, EvmConfig, Network, Tasks, Events, EthApi> =
	Box<dyn FnOnce(&EthApiBuilderCtx<Provider, Pool, EvmConfig, Network, Tasks, Events>) -> EthApi>;

and

reth/crates/node/builder/src/rpc.rs

Line 359 in bf44c97

eth_api_builder: impl FnOnce(&EthApiBuilderCtx<Node>) -> EthApi + Send + Sync + 'static,

as the constructor for the EthApi, like:

reth/crates/rpc/rpc/src/eth/core.rs

Lines 99 to 106 in bf44c97

	/// Creates a new, shareable instance.
	pub fn with_spawner<Tasks, Events>(
	ctx: &EthApiBuilderCtx<Provider, Pool, EvmConfig, Network, Tasks, Events>,
	) -> Self
	where
	Tasks: TaskSpawner + Clone + 'static,
	Events: CanonStateSubscriptions,
	{

and

reth/crates/optimism/node/src/node.rs

Line 147 in bf44c97

Self(RpcAddOns::new(move |ctx| OpEthApi::new(ctx, sequencer_http), Default::default()))

this makes it very difficult to navigate and is a bit confusing. With a trait it would be easier to find all places where this is used.

TODO

• replace Boxed closure with a boxed trait instead

  reth/crates/node/builder/src/rpc.rs

  Line 338 in bf44c97

  eth_api_builder: Box<dyn FnOnce(&EthApiBuilderCtx<Node>) -> EthApi + Send + Sync>,

Additional context

No response