Enable mutual close and penalty txns through peer storage

[adi2011]

Currently, we have:

• Peer storage, which contains static channel backup used for node recovery.

I propose we extend it to include the following:

1. Extend peer storage to include the latest channel balances and counterparty commitment secrets.
2. Update peer storage more frequently—if viable—after each RAA.
3. Introduce the ability to perform peer backups for random nodes in exchange for sats.
4. Enable CLN to either initiate a mutual close or sweep funds via penalty transactions if the peer broadcasts an outdated state.