Add image-pull-policy field for karmada-operator

[seanlaii]

What type of PR is this?

/kind feature

What this PR does / why we need it:
#4789

Which issue(s) this PR fixes:
Part of #4789

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Allow the user to specify `imagePullPolicy` in Karmada CR when installing via karmada-operator.

[karmada-bot]

Welcome @seanlaii! It looks like this is your first PR to karmada-io/karmada 🎉

[XiShanYongYe-Chang]

@seanlaii Thanks a lot~
/cc @calvin0327 @zhzhuang-zju

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.98%. Comparing base (20bb7a7) to head (d78ea38).
Report is 16 commits behind head on master.

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4863      +/-   ##
==========================================
- Coverage   53.05%   52.98%   -0.08%     
==========================================
  Files         250      250              
  Lines       20371    20421      +50     
==========================================
+ Hits        10808    10820      +12     
- Misses       8845     8882      +37     
- Partials      718      719       +1     

Flag	Coverage Δ
unittests	52.98% <ø> (-0.08%)	⬇️

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[zhzhuang-zju]

@seanlaii nice job~ /lgtm

btw, we can continous to push forward #4401 to add validation of the installation method of the operatoris installed. @XiShanYongYe-Chang

[zhzhuang-zju]

/lgtm

[calvin0327]

/lgtm

thanks for doing this.

[XiShanYongYe-Chang]

Ask an approve from @RainbowMango
/assign @RainbowMango

[RainbowMango]

/approve
For the API part.

[karmada-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: RainbowMango

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