Introduce a block execution abstraction

[ferranbt]

Right now the way we include transactions in the block is pretty verbose and hard to extend if we assume we are going into a direction in which we want to have more flexibility around block building (apply batches of transactions, revert back to a given state, etc...). Introduce a BlockExecutor utility that abstracts away all that boilerplate.

Initially, the API can be just a wrapper around the current Reth BlockState like:

let state = State::new();
let executor = BlockState::new();
let result = executor.apply(tx);
state.commit(state);

but the medium term goal is to add something more optimised for our block building use case like:

let state = State::new();
let executor = BlockState::new()
let snap = state.snapshot();
let result = executor.apply(snap, tx);

In this case, the interface handles execution reverts of the state, something that it is less likely to be optimised in Reth.