Fix the problem that dashboard do not correctly show the SystemRule in CPU usage strategy

[Crazy10552]

it fix the bug that dashboard do not correctly show the system rule(the rule about properties highestCpuUsage)

Does this pull request fix one issue?

Fixes #905

Describe how you did it

• I add new properties in entity SystemRuleEntity

• I update the related js and html about System rule

Describe how to verify it

Special notes for reviews

i recreate my branch to slove my commit problem of my git account,the previous pull pull922

[codecov-io]

Codecov Report

Merging #927 into master will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #927      +/-   ##
============================================
- Coverage     42.54%   42.53%   -0.02%     
  Complexity     1441     1441              
============================================
  Files           310      310              
  Lines          8993     8993              
  Branches       1222     1222              
============================================
- Hits           3826     3825       -1     
- Misses         4698     4699       +1     
  Partials        469      469

Impacted Files	Coverage Δ	Complexity Δ
...tinel/slots/block/flow/param/ParamFlowChecker.java	52.7% <0%> (-2.71%)	28% <0%> (-1%)
...inel/datasource/zookeeper/ZookeeperDataSource.java	66.33% <0%> (-1%)	15% <0%> (-1%)
...a/csp/sentinel/slots/statistic/base/LeapArray.java	70.29% <0%> (+2.97%)	34% <0%> (+1%)	⬆️
...ava/com/alibaba/csp/sentinel/node/ClusterNode.java	100% <0%> (+4.76%)	8% <0%> (+1%)	⬆️

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[sczyh30]

LGTM

[sczyh30]

Thanks for contributing! I'll refine the code later.