*: move kv to pkg

[rleungx]

Signed-off-by: Ryan Leung rleungx@gmail.com

What problem does this PR solve?

Issue Number: Ref #5838.

What is changed and how does it work?

This PR moves kv package from server to pkg so that tso logic won't rely on the server.

Check List

Tests

• Unit test

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• lhy1024
• nolouch

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[codecov]

Codecov Report

Base: 75.61% // Head: 75.65% // Increases project coverage by +0.04% 🎉

Coverage data is based on head (2c728a4) compared to base (776003b).
Patch has no changes to coverable lines.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5773      +/-   ##
==========================================
+ Coverage   75.61%   75.65%   +0.04%     
==========================================
  Files         329      329              
  Lines       32965    32957       -8     
==========================================
+ Hits        24925    24933       +8     
+ Misses       5896     5882      -14     
+ Partials     2144     2142       -2     

Flag	Coverage Δ
unittests	75.65% <ø> (+0.04%)	⬆️

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

Impacted Files	Coverage Δ
pkg/election/leadership.go	75.25% <ø> (ø)
pkg/storage/kv/etcd_kv.go	79.71% <ø> (ø)
pkg/storage/kv/levedb_kv.go	86.95% <ø> (ø)
pkg/storage/kv/mem_kv.go	100.00% <ø> (ø)
pkg/storage/kv/metrics.go	100.00% <ø> (ø)
server/config/store_config.go	81.60% <ø> (ø)
server/grpc_service.go	49.79% <ø> (+0.16%)	⬆️
server/id/id.go	86.44% <ø> (+3.38%)	⬆️
server/member/member.go	64.21% <ø> (-1.58%)	⬇️
server/region_syncer/history_buffer.go	78.46% <ø> (ø)
... and 34 more

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[nolouch]

/merge

[ti-chi-bot]

@nolouch: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

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[ti-chi-bot]

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

Commit hash: 68ddc9a

[binshi-bing]

reviewed