Add support for option_shutdown_anysegwit

[t-bast]

Opt-in to allow any future segwit script in shutdown as long as it complies with BIP 141 (see lightning/bolts#672).

This has been tested successfully against c-lightning v0.10.0 compiled with --enable-experimental-features.

[codecov-commenter]

Codecov Report

Merging #1801 (a46c1aa) into master (340fd29) will decrease coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1801      +/-   ##
==========================================
- Coverage   89.33%   89.30%   -0.04%     
==========================================
  Files         143      143              
  Lines       10932    10936       +4     
  Branches      481      476       -5     
==========================================
  Hits         9766     9766              
- Misses       1166     1170       +4     

Impacted Files	Coverage Δ
...core/src/main/scala/fr/acinq/eclair/Features.scala	98.97% <100.00%> (+0.03%)	⬆️
...c/main/scala/fr/acinq/eclair/channel/Channel.scala	86.41% <100.00%> (-0.07%)	⬇️
...c/main/scala/fr/acinq/eclair/channel/Helpers.scala	95.94% <100.00%> (+0.01%)	⬆️
...clair/blockchain/bitcoind/rpc/BatchingClient.scala	86.36% <0.00%> (-13.64%)	⬇️
...main/scala/fr/acinq/eclair/io/PeerConnection.scala	84.68% <0.00%> (-0.43%)	⬇️
...re/src/main/scala/fr/acinq/eclair/NodeParams.scala	92.65% <0.00%> (-0.13%)	⬇️
...cala/fr/acinq/eclair/crypto/TransportHandler.scala	90.76% <0.00%> (+0.54%)	⬆️