Add option to disable sending remote address in init

[t-bast]

When running behind a load balancer that doesn't preserve the client source IP address, it doesn't make sense to include the remote-address tlv in our init message, it will contain an IP address that is completely unrelated to our peer.

Fixes #2256

[codecov-commenter]

Codecov Report

Merging #2285 (4a38cd1) into master (9c7ddcd) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2285      +/-   ##
==========================================
+ Coverage   84.32%   84.33%   +0.01%     
==========================================
  Files         194      194              
  Lines       14411    14412       +1     
  Branches      567      591      +24     
==========================================
+ Hits        12152    12155       +3     
+ Misses       2259     2257       -2     

Impacted Files	Coverage Δ
...re/src/main/scala/fr/acinq/eclair/NodeParams.scala	92.80% <100.00%> (+0.02%)	⬆️
...main/scala/fr/acinq/eclair/io/PeerConnection.scala	85.98% <100.00%> (ø)
...cinq/eclair/remote/EclairInternalsSerializer.scala	97.77% <100.00%> (ø)
...in/scala/fr/acinq/eclair/channel/fsm/Channel.scala	88.39% <0.00%> (ø)
...cala/fr/acinq/eclair/payment/relay/NodeRelay.scala	97.56% <0.00%> (+1.62%)	⬆️

[pm47]

I'm not sure this is really necessary (we could fix our deployment, it's as simple as advertising a different public ip), but it doesn't cost much to support not sending the tlv, so I'll leave it to you to decide.

[pm47]

Should be bool8 but apparently we have other "violations" in that file.

[t-bast]

I saw that, that's why I chose to be consistent instead of using bool8. I'll do a follow-up tiny refactoring to move to bool8 everywhere in another PR.

[t-bast]

we could fix our deployment, it's as simple as advertising a different public ip

But if we advertise the IP that doesn't go through the load balancer, it negates the benefits of having a load balancer, doesn't it?
I think having the option to turn this off can be useful and doesn't add too much code, because we don't know yet what setup other node operators will use and they may not always be able to have access to the real client IP.