Merge pull request #2697 from jkczyz/2023-10-offer-functional-tests

Functional tests for BOLT 12 Offers payment flow

diff --cc lightning/src/ln/channelmanager.rs
Simple merge

diff --cc lightning/src/ln/outbound_payment.rs
Simple merge

diff --cc lightning/src/ln/peer_handler.rs
Simple merge

diff --cc lightning/src/routing/router.rs
Simple merge

diff --cc lightning/src/sign/mod.rs
Simple merge