Cleanup of -debug=net log messages
Summary:
A few changes to -debug=net logging: - always log when disconnecting a peer - only log various connection errors when -debug=net is enabled, since errors from random untrusted peers is completely expected - log when ignoring a message due to violating protocol (primarily to make it easier to debug other implementations) - use "peer=123" rather than "from 123" to make grepping logs a bit easier - log the value of the bip-37 fRelay field in version messages both when sending and receiving a version message
Some differences from the source material are due to segwit and out of order backports.
Backport of core#20724.
Ref T1696.
Test Plan:
ninja all check-extended
Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Maniphest Tasks: T1696
Differential Revision: https://reviews.bitcoinabc.org/D10923