[DUBBO-3137]: step2 - seperate constants for cluster, common, filter, monitor, and registry

[beiwei30]

What is the purpose of the change

issue #3137: step 2

Brief changelog

XXXXX

Verifying this change

XXXXX

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[CrazyHZM]

LGTM

[chickenlj]

LGTM

[codecov-io]

Codecov Report

Merging #4020 into master will decrease coverage by 0.04%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##             master   #4020      +/-   ##
===========================================
- Coverage     63.44%   63.4%   -0.05%     
- Complexity      564     565       +1     
===========================================
  Files           751     754       +3     
  Lines         32415   32423       +8     
  Branches       5145    5145              
===========================================
- Hits          20567   20558       -9     
- Misses         9489    9508      +19     
+ Partials       2359    2357       -2

Impacted Files	Coverage Δ	Complexity Δ
...ache/dubbo/common/constants/RegistryConstants.java	0% <0%> (ø)	0 <0> (?)
...ubbo/common/constants/MetadataReportConstants.java	0% <0%> (ø)	0 <0> (?)
...apache/dubbo/common/constants/CommonConstants.java	0% <0%> (ø)	0 <0> (?)
...ng/exchange/support/header/HeartbeatTimerTask.java	73.68% <0%> (-5.27%)	0% <0%> (ø)
...g/apache/dubbo/rpc/protocol/rest/RestProtocol.java	67.96% <0%> (-3.13%)	0% <0%> (ø)
...pache/dubbo/registry/support/AbstractRegistry.java	78.54% <0%> (-3.07%)	0% <0%> (ø)
...dubbo/remoting/exchange/support/DefaultFuture.java	71.42% <0%> (-2.05%)	0% <0%> (ø)
... and 4 more

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