cluster: return error when found multiple nodes with the same ip:port

[srstack]

What problem does this PR solve?

close #1854

I think that when there are multiple nodes with the same ip:port, an error should be returned and the client should check.

Release notes:

NONE

[ti-chi-bot]

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• AstroProfundis

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[codecov-commenter]

Codecov Report

Merging #1856 (6421cd7) into master (ebde574) will increase coverage by 0.60%.
The diff coverage is 41.51%.

@@            Coverage Diff             @@
##           master    #1856      +/-   ##
==========================================
+ Coverage   51.93%   52.53%   +0.60%     
==========================================
  Files         306      306              
  Lines       35109    35133      +24     
==========================================
+ Hits        18233    18457     +224     
+ Misses      14693    14490     -203     
- Partials     2183     2186       +3     

Flag	Coverage Δ
cluster	40.88% <41.51%> (+0.93%)	⬆️
dm	24.53% <0.00%> (-0.02%)	⬇️
playground	12.74% <0.00%> (-0.02%)	⬇️
tiup	14.36% <0.00%> (-0.07%)	⬇️
unittest	21.20% <0.00%> (-0.02%)	⬇️

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

Impacted Files	Coverage Δ
pkg/cluster/api/binlog.go	38.74% <41.51%> (+2.82%)	⬆️
pkg/utils/http_client.go	46.56% <0.00%> (-2.29%)	⬇️
pkg/repository/store/txn.go	56.91% <0.00%> (-2.13%)	⬇️
pkg/cluster/manager/scale_out.go	41.33% <0.00%> (+0.51%)	⬆️
pkg/cluster/manager/builder.go	73.09% <0.00%> (+0.64%)	⬆️
pkg/cluster/manager/display.go	49.47% <0.00%> (+0.89%)	⬆️
pkg/cluster/operation/action.go	62.53% <0.00%> (+0.92%)	⬆️
pkg/cluster/executor/ssh.go	64.10% <0.00%> (+1.10%)	⬆️
pkg/cluster/spec/monitoring.go	67.80% <0.00%> (+1.55%)	⬆️
... and 14 more

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[AstroProfundis]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 6421cd7