Track HTLC-failure trigger tx until anti-reorg delay reached
Broadcasting a commitment tx means that we have to fail
inbound HTLC in backward channel. Doing it prematurely would
put us at risk in case of reorg. So we delay passing failure
update upstream until solving tx mature to HTLC_FAIL_ANTI_
REORG_DELAY.
Requirements differ if HTLC is a revoked/non-revoked dust/
non-revoked non-dust one.
Add connect_blocks in test_utils to fix broken tests due to
anti-reorg delay enforcement
Remove anti-duplicate htlc update stuff in ManySimpleChannelMonitor