Revert #13712

[liggitt]

Reverts the PR #13712 and adds a unit test for correct handling of canonical SRV records.

xref #13948

/cc @serathius @spzala @ahrtr

[spzala]

lgtm
@liggitt thanks so much for it and the discussion in the issue.
Also, re-running failed tests.
cc @serathius @ahrtr @ptabor

[codecov-commenter]

Codecov Report

Merging #13949 (f07745a) into main (93c54b8) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #13949      +/-   ##
==========================================
- Coverage   72.49%   72.48%   -0.01%     
==========================================
  Files         469      469              
  Lines       38414    38413       -1     
==========================================
- Hits        27848    27844       -4     
- Misses       8777     8782       +5     
+ Partials     1789     1787       -2     

Flag	Coverage Δ
all	72.48% <ø> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
server/proxy/grpcproxy/register.go	69.76% <0.00%> (-9.31%)	⬇️
client/v3/leasing/util.go	91.66% <0.00%> (-6.67%)	⬇️
raft/rafttest/node.go	95.00% <0.00%> (-5.00%)	⬇️
server/etcdserver/api/v3rpc/member.go	93.54% <0.00%> (-3.23%)	⬇️
server/etcdserver/api/v3election/election.go	66.66% <0.00%> (-2.78%)	⬇️
pkg/traceutil/trace.go	96.15% <0.00%> (-1.93%)	⬇️
server/storage/mvcc/kvstore_txn.go	75.27% <0.00%> (-1.10%)	⬇️
server/etcdserver/api/v3rpc/watch.go	85.90% <0.00%> (-0.68%)	⬇️
server/storage/mvcc/watchable_store.go	89.13% <0.00%> (-0.37%)	⬇️
server/etcdserver/server.go	84.54% <0.00%> (-0.33%)	⬇️
... and 13 more

---

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[ahrtr]

Two comments:

1. This PR needs to rebase, because I recently reverted the change which causes the pipeline failures, see 13945 ;
2. Please hold on merging this PR until it's clearly clarified in 13948

[liggitt]

rebased, and replied in #13948 (comment)

[ahrtr]

LGTM

Thank you.

Please refer to the discussion in issues/13948