Use psbt to fund and sign transactions

[sstone]

No description provided.

[codecov-commenter]

Codecov Report

Merging #1876 (b4eb3cc) into master (273fae9) will decrease coverage by 0.02%.
The diff coverage is 81.25%.

@@            Coverage Diff             @@
##           master    #1876      +/-   ##
==========================================
- Coverage   87.65%   87.63%   -0.03%     
==========================================
  Files         158      158              
  Lines       12406    12467      +61     
  Branches      515      525      +10     
==========================================
+ Hits        10875    10925      +50     
- Misses       1531     1542      +11     

Impacted Files	Coverage Δ
...-core/src/main/scala/fr/acinq/eclair/package.scala	65.57% <37.50%> (-9.99%)	⬇️
...c/main/scala/fr/acinq/eclair/channel/Channel.scala	88.27% <66.66%> (ø)
...ir/blockchain/bitcoind/rpc/BitcoinCoreClient.scala	88.75% <88.23%> (-5.49%)	⬇️
...clair/channel/publish/ReplaceableTxPublisher.scala	87.70% <92.85%> (+1.81%)	⬆️
...ir-core/src/main/scala/fr/acinq/eclair/Setup.scala	80.45% <100.00%> (ø)
...main/scala/fr/acinq/eclair/router/Validation.scala	92.30% <0.00%> (+1.53%)	⬆️

[t-bast]

While reading this PR, I realized that:

• the separation between ExtendedBitcoinClient and BitcoinCoreWallet doesn't make sense anymore, so I removed it in Clean up inconsistency between bitcoin client and wallet #1939 (which should be a pre-requisite for this PR)
• I added the address conversion utilities to bitcoin-lib in Add support for Bech32m (BIP 350) bitcoin-lib#55 (with compatibility with future segwit versions)
• handling psbts is a bit messy: we only have a single PartiallySignedInput type which doesn't reflect the state of the input and has optional fields everywhere, which makes it hard to check the progress of a psbt's inputs. I've done a big refactoring to add more types and make psbts more pleasant to work with in Improve PSBT types bitcoin-lib#60, I'm curious to have your feedback. I think it's important to nail down the right abstraction for psbt before we start using it widely inside eclair (e.g. we need to be very careful when we sign psbts, we must for example check sighash flags in case the other party modified it)

[sstone]

Superseded by #2120