Remove redundant bolt11_payment.rs

With `pay_for_bolt11_invoice` now handling payment and route parameter
extraction within `ChannelManager`, the utility functions in
`bolt11_payment.rs` have become unnecessary. This commit removes the
redundant code and associated tests, streamlining the implementation.

Author: shaavan

lightning/src/ln/bolt11_payment.rs

@@ -2032,9 +2032,6 @@ where
 /// # }
 /// ```
 ///
-/// For paying an invoice, see the [`bolt11_payment`] module with convenience functions for use with
-/// [`send_payment`].
-///
 /// ```
 /// # use bitcoin::hashes::Hash;
 /// # use lightning::events::{Event, EventsProvider};
@@ -2360,7 +2357,6 @@ where
 /// [`create_bolt11_invoice`]: Self::create_bolt11_invoice
 /// [`create_inbound_payment`]: Self::create_inbound_payment
 /// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
-/// [`bolt11_payment`]: crate::ln::bolt11_payment
 /// [`claim_funds`]: Self::claim_funds
 /// [`send_payment`]: Self::send_payment
 /// [`offers`]: crate::offers

lightning/src/ln/channelmanager.rs

@@ -28,7 +28,6 @@ pub mod types;
 // TODO: These modules were moved from lightning-invoice and need to be better integrated into this
 // crate now:
 pub mod invoice_utils;
-pub mod bolt11_payment;
 
 #[cfg(fuzzing)]
 pub mod peer_channel_encryptor;