support yurthub component work in specified namespace

[huweihuang]

What type of PR is this?

/kind feature

What this PR does / why we need it:

What would you like to be added:
yurthub component should be deployed in kube-system namespace. as you known, kube-system namespace is used for K8s components, so some users have requested that yurthub can be deployed in specified namespace.

Why is this needed:
improve the deployment flexibility of OpenYurt component.

Which issue(s) this PR fixes:

Fixes # #1341

Does this PR introduce a user-facing change?

add a parameter for yurthub to specify namespace variable.

and update the yurthub.yaml namespace as specify namespace

[huweihuang]

@rambohe-ch please help to review it.

[codecov]

Codecov Report

Merging #1366 (2c16022) into master (228240a) will increase coverage by 0.01%.
The diff coverage is 64.28%.

@@            Coverage Diff             @@
##           master    #1366      +/-   ##
==========================================
+ Coverage   52.13%   52.15%   +0.01%     
==========================================
  Files         107      107              
  Lines       13462    13466       +4     
==========================================
+ Hits         7019     7023       +4     
  Misses       5853     5853              
  Partials      590      590              

Flag	Coverage Δ
unittests	52.15% <64.28%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
cmd/yurthub/app/config/config.go	53.61% <50.00%> (+0.35%)	⬆️
cmd/yurthub/app/options/options.go	94.73% <100.00%> (+0.06%)	⬆️
...yurthub/poolcoordinator/certmanager/certmanager.go	75.89% <100.00%> (ø)

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[rambohe-ch]

constants.PoolCoordinatorClientSecretNamespace should be replaced with options.YurtHubNamespace, because yurthub use this ns to get secret from cloud kube-apiserver.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

No Coverage information
0.0% Duplication

[openyurt-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: huweihuang, rambohe-ch

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• OWNERS [rambohe-ch]

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[rambohe-ch]

/lgtm