p2p: Restore OriginalAddr

[ebuchman]

Fixes #2618

• Updated all relevant documentation in docs
• Updated all code comments where relevant
• Wrote tests
• Updated CHANGELOG_PENDING.md

[codecov-io]

Codecov Report

Merging #2668 into develop will increase coverage by 0.11%.
The diff coverage is 90%.

@@             Coverage Diff             @@
##           develop    #2668      +/-   ##
===========================================
+ Coverage    61.61%   61.72%   +0.11%     
===========================================
  Files          207      207              
  Lines        16928    16944      +16     
===========================================
+ Hits         10430    10459      +29     
+ Misses        5628     5621       -7     
+ Partials       870      864       -6

Impacted Files	Coverage Δ
p2p/test_util.go	66.66% <100%> (+0.25%)	⬆️
p2p/transport.go	80.36% <100%> (+0.18%)	⬆️
p2p/switch.go	51.65% <33.33%> (-0.35%)	⬇️
p2p/peer.go	60.41% <90.9%> (+2.52%)	⬆️
consensus/state.go	76.52% <0%> (+0.58%)	⬆️
consensus/reactor.go	72% <0%> (+1.41%)	⬆️

[ebuchman]

@melekes would appreciate review on this but I'm going to merge for now so I can start prepping the v0.26.0 release