Add Bookkeeper Support

[ShahanaFarooqui]

Currently, Greenlight does not support integration with the Bookkeeper plugin, which is an accounting system designed for Core Lightning nodes. By adding Bookkeeper support, Greenlight nodes would gain enhanced accounting capabilities, enabling users to track and manage financial data (e.g., payments, invoices, forwards, and channel balances) more effectively. This would provide users with better insights into their node's financial activity and improve overall node management.

[cdecker]

We are currently discussing on how to enable persistence for bkpr's datastore. For context: bkpr creates its own sqlite3 database in the lightning-dir on startup, and then starts tracking funds by annotating coin movements with additional information.

Since Greenlight purges the slots that nodes are scheduled in after shutdown, to make the slot available to other nodes, we also lose the bkpr DB. We have a couple of options, and will either store the DB separately, merge the bkpr database with the node database, or reimplement bkpr with better integration into Greenlight.

Stay tuned 📻