Enhance Karmada UT coverage

[realnumber666]

What would you like to be added:
Improve the UT coverage from 49% to 69% (↑20%)

Why is this needed:
To improve the reliability of the Karmada project, verify the implementation and usability of functions, and improve user experience.

Plan:
For maximum efficiency, I will start with the files and folders with the most missed lines.

• Improve UT coverage of pkg from 49% to 80%
• Improve UT coverage of cmd from 31% to 69%
• Improve UT coverage of examples from 64% to 69%

Here is the reference for the UT coverage link

[XiShanYongYe-Chang]

Although the target has not been achieved, we have already covered the majority of code that does not involve controller components. Moving forward, we will continue to maintain and improve code coverage.
/close

[karmada-bot]

@XiShanYongYe-Chang: Closing this issue.

In response to this:

Although the target has not been achieved, we have already covered the majority of code that does not involve controller components. Moving forward, we will continue to maintain and improve code coverage.
/close

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