Merge pull request #2312 from TheBlueMatt/2023-05-next-htlc-min-max

Avoid generating unpayable routes due to balance restrictions

diff --cc fuzz/src/chanmon_consistency.rs
Simple merge

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

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

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

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

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