client: support create with context

[disksing]

Signed-off-by: disksing i@disksing.com

What problem does this PR solve?

Cherry-pick #1993

What is changed and how it works?

add NewClientWithContext

Check List

Tests

• Unit test

Related changes

• Need to be included in the release notes

[rleungx]

/run-all-tests

[codecov-io]

Codecov Report

Merging #1994 into release-3.0 will increase coverage by 0.2%.
The diff coverage is 90%.

@@              Coverage Diff               @@
##           release-3.0    #1994     +/-   ##
==============================================
+ Coverage        69.32%   69.52%   +0.2%     
==============================================
  Files              170      170             
  Lines            16757    16764      +7     
==============================================
+ Hits             11616    11655     +39     
+ Misses            4157     4136     -21     
+ Partials           984      973     -11

Impacted Files	Coverage Δ
client/client.go	73.81% <90%> (+2.57%)	⬆️
server/schedulers/random_merge.go	62.5% <0%> (-5%)	⬇️
server/namespace_cluster.go	81.81% <0%> (-3.9%)	⬇️
server/cluster.go	81.72% <0%> (-0.51%)	⬇️
server/handler.go	52.11% <0%> (+0.49%)	⬆️
server/grpc_service.go	59.27% <0%> (+0.63%)	⬆️
server/tso.go	76.59% <0%> (+2.12%)	⬆️
server/leader.go	82.04% <0%> (+2.85%)	⬆️
server/util.go	75.15% <0%> (+7%)	⬆️
... and 1 more

---

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[rleungx]

LGTM

[lhy1024]

/merge

[sre-bot]

Your auto merge job has been accepted, waiting for 1995

[sre-bot]

/run-all-tests