feat(rpc): Convert state_at_block_id into async function

[RomanHodulak]

Follow-up on #17924

This makes the existing state_at_block_id async, despite them not having any async call at the moment. This is a preparation for introducing async pending_state function and calling it inside this function.

There are two places that previously used spawn_tracing that were replaced with spawn_blocking_io_fut.

1. https://github.com/paradigmxyz/reth/blob/main/crates/rpc/rpc-eth-api/src/helpers/call.rs#L541
2. https://github.com/paradigmxyz/reth/blob/main/crates/rpc/rpc-eth-api/src/helpers/trace.rs#L305

I haven't found a simple way to make spawn_tracing accept futures, nor am I sure that such thing makes sense. However, the call place is not really benefiting from using the rayon pool, which is what spawn_tracing is used for. And the second place, the trace API, might benefit from it, but trace API is not affecting production path, hence it is not as speed critical.

If we really wanted to keep spawn_tracing, one idea is to also put the async call to state_at_block_id outside of the callback. This, however, causes a mysterious higher-ranked lifetime error - I tried a few simple fixes unsuccessfully like:

• Introducing use<>
• Making a use of StateProviderTraitObjWrapper

[mattsse]

makes sense

most existing trace calls that were previously spawned on rayon pool do a lot of IO and should really be spawned on blocking