Redact sensitive information from the karmadactl init command output

[zhzhuang-zju]

What type of PR is this? /kind feature

What this PR does / why we need it: The karmadactl init command, at the end of the initializtaion, writes some sensitive information in the stdout, like token, in its karmadactl register example. This will bring up two issues：

• data leak, for instance in CI/CD logs

• The token's validity period is one day. Users may not join the pull mode member clusters immediately after installing Karmada, causing the secret to expire.

I hope the command output to be how to do rather than what to do. Users can follow the steps in the command output as needed.

Which issue(s) this PR fixes: Fixes #

Special notes for your reviewer: Modified command output:

Register cluster with 'Pull' mode

Step 1: Create bootstrap tokens and get the full 'karmadactl register' flag needed to register the member cluster using the token.
(In karmada)~# karmadactl token create --print-register-command --kubeconfig /etc/init/members/karmada-apiserver.config
karmadactl register [karmada-apiserver-endpoint] --token [token] --discovery-token-ca-cert-hash [ca-cert-hash]

Step 2: Use the output result from step 1 to register the cluster to Karmada control plane. "--cluster-name" is set to cluster of current-context by default.
(In member cluster)~# karmadactl register [karmada-apiserver-endpoint] --token [token] --discovery-token-ca-cert-hash [ca-cert-hash]

Step 3: Show members of karmada
(In karmada)~# karmadactl --kubeconfig /etc/init/members/karmada-apiserver.config get clusters

Does this PR introduce a user-facing change?:

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Codecov Report

Attention: Patch coverage is 94.44444% with 1 line in your changes missing coverage. Please review.

Project coverage is 46.24%. Comparing base (72cfef5) to head (429f2d3). Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/karmadactl/cmdinit/kubernetes/deploy.go	0.00%	1 Missing :warning:

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5714      +/-   ##
==========================================
+ Coverage   46.18%   46.24%   +0.05%     
==========================================
  Files         663      663              
  Lines       54592    54575      -17     
==========================================
+ Hits        25215    25236      +21     
+ Misses      27752    27717      -35     
+ Partials     1625     1622       -3     

Flag	Coverage Δ
unittests	46.24% <94.44%> (+0.05%)	:arrow_up:

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[zhzhuang-zju]

/assign @RainbowMango

[RainbowMango]

OK. Please rebase the code to make the new tests happy.

[karmada-bot]

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This pull-request has been approved by: RainbowMango

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