Merge pull request #1861 from TheBlueMatt/2022-11-tx-connection-idempotency

Ensure transactions_confirmed is idempotent

diff --cc lightning/src/chain/channelmonitor.rs
Simple merge

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

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

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