feat: ForkChoiceSubscriptions for BlockchainProvider && NoopProvidor

[royvardhan]

Ref 9521

[mattsse]

hmm, after looking at this again, I'd like to take one step back and only implement this for BlockChainProvider and Noop.

blockchainprovider then should use these channels to obtain the listeners,

reth/crates/chain-state/src/chain_info.rs

Lines 139 to 144 in e907f0e

	/// The canonical head of the chain.
	canonical_head: RwLock<SealedHeader>,
	/// The block that the beacon node considers safe.
	safe_block: watch::Sender<Option<SealedHeader>>,
	/// The block that the beacon node considers finalized.
	finalized_block: watch::Sender<Option<SealedHeader>>,

which means we also need to change this type slightly

reth/crates/chain-state/src/notifications.rs

Line 146 in e907f0e

pub struct ForkChoiceNotifications(broadcast::Receiver<SealedHeader>);

[mattsse]

Suggested change