Split out the context cache from the consensus crate

[Boog900]

What

The context cache is the service in cuprate-consensus that caches data from the database, this issue is for splitting it into a separate crate.

Why

We should pass in the data needed to verify a tx/block we shouldn't hold the context service in the verifiers. Splitting it into a separate crate makes this clearer.

[hinto-janai]

@Boog900 @SyntheticBird45 is this closed by #318?

[SyntheticBird45]

@hinto-janai As far as I understand it, there is a still second part to be achieved regarding the Why section

[Boog900]

The crate should be completed separated, cuprate-consensus shouldn't depend on the context crate