Add: add SetLoggerLevel

[fangyincheng]

What this PR does:

add SetLoggerLevel to dynamically modify logger level.

Which issue(s) this PR fixes:

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[codecov-io]

Codecov Report

Merging #271 into develop will increase coverage by 0.05%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop     #271      +/-   ##
===========================================
+ Coverage    66.38%   66.43%   +0.05%     
===========================================
  Files          111      111              
  Lines         7038     7047       +9     
===========================================
+ Hits          4672     4682      +10     
+ Misses        1907     1905       -2     
- Partials       459      460       +1

Impacted Files	Coverage Δ
common/logger/logger.go	94.82% <100%> (+11.15%)	⬆️
config_center/apollo/impl.go	84.41% <0%> (-2.6%)	⬇️
cluster/cluster_impl/failback_cluster_invoker.go	78.49% <0%> (-2.16%)	⬇️

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[AlexStocks]

@pantianying pls review this pr.

[pantianying]

LGTM