Add LSPS2 BOLT12 custom router

Introduce a router wrapper that maps BOLT12 offer ids to LSPS2 invoice parameters and injects intercept-SCID blinded payment paths while delegating all other routing logic to an inner router.

Co-Authored-By: HAL 9000

Author: tnull

lightning-liquidity/src/lsps2/mod.rs

@@ -13,5 +13,6 @@ pub mod client;
 pub mod event;
 pub mod msgs;
 pub(crate) mod payment_queue;
+pub mod router;
 pub mod service;
 pub mod utils;