Use satoshi for htlc ordering

[pm47]

Reproduce and fix the spec violation. Updated the test vectors according to lightning/bolts#872 (comment).

Fixes #1804.

[codecov-commenter]

Codecov Report

Merging #1806 (e6e1cc1) into master (898c17b) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1806   +/-   ##
=======================================
  Coverage   89.31%   89.31%           
=======================================
  Files         143      143           
  Lines       10929    10929           
  Branches      468      468           
=======================================
  Hits         9761     9761           
  Misses       1168     1168           

Impacted Files	Coverage Δ
...la/fr/acinq/eclair/transactions/Transactions.scala	96.78% <100.00%> (ø)
...cala/fr/acinq/eclair/payment/relay/NodeRelay.scala	96.09% <0.00%> (-1.57%)	⬇️
...c/main/scala/fr/acinq/eclair/channel/Channel.scala	86.31% <0.00%> (+0.08%)	⬆️
...main/scala/fr/acinq/eclair/io/PeerConnection.scala	85.10% <0.00%> (+0.42%)	⬆️

[t-bast]

Good catch!