*: refine log in some packages (#2885)

[ti-srebot]

cherry-pick #2885 to release-4.0

---

What problem does this PR solve?

Part of #2704.

What is changed and how it works?

This PR refines logs in some packages according to RFC.

Check List

Tests

• Unit test

Related changes

• Need to cherry-pick to the release branch

Release note

[codecov]

Codecov Report

Merging #2913 into release-4.0 will decrease coverage by 0.00%.
The diff coverage is 36.92%.

@@               Coverage Diff               @@
##           release-4.0    #2913      +/-   ##
===============================================
- Coverage        77.34%   77.34%   -0.01%     
===============================================
  Files              210      209       -1     
  Lines            22854    22847       -7     
===============================================
- Hits             17676    17670       -6     
+ Misses            3839     3834       -5     
- Partials          1339     1343       +4     

Impacted Files	Coverage Δ
server/api/member.go	60.00% <0.00%> (ø)
server/core/region_storage.go	81.81% <0.00%> (ø)
server/core/region_tree.go	93.27% <0.00%> (ø)
server/grpc_service.go	60.90% <0.00%> (+0.75%)	⬆️
server/member/leader.go	71.53% <0.00%> (-0.77%)	⬇️
server/region_syncer/server.go	80.55% <0.00%> (ø)
server/schedule/region_scatterer.go	86.14% <0.00%> (-0.53%)	⬇️
server/kv/levedb_kv.go	78.37% <25.00%> (-4.48%)	⬇️
server/schedule/operator_controller.go	81.41% <28.57%> (ø)
server/cluster/cluster.go	80.89% <33.33%> (-0.02%)	⬇️
... and 17 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b510897...4e80605. Read the comment docs.

[rleungx]

/merge

[ti-srebot]

/run-all-tests