Chore: add unit test

[yyzxw]

Description of your changes

Hi, I am very honored to participate in Kubevela. This is my first contribution. This PR has added some unit tests.

🤖 Generated by Copilot at 889a6e9

Summary

🧪🛠️📝

This pull request fixes some compile errors and adds new test functions for various utility packages. It improves the test coverage and quality of the pkg/utils/schema, pkg/utils/system, pkg/utils/url, pkg/utils/file, and pkg/utils/strings packages. It also tests the validation of UI schemas for the pkg/utils/schema package.

Some changes were made to the code
To test some functions and modes
They imported fmt and assert
And checked some files and some words
And fixed some errors that showed

Walkthrough

• Add new test functions to improve test coverage and quality of the utils package (link, link, link)

• Test the IsJSONYAMLorCUEFile function, which checks file extensions (link)
• Test the StringsContain function, which checks string slices (link)
• Test the IsValidURL function, which checks URL validity (link)

• Add new test functions to improve test coverage and quality of the schema package (link)
  • Test the Validate method of the UISchema type, which validates UI schema conditions and actions (link)
• Add new test functions to improve test coverage and quality of the system package (link)
  • Test the GetVelaHomeDir function, which returns the vela home directory (link)
• Add missing import statements to fix compile errors and enable testing of the utils, schema, and system packages (link, link, link)

Fixes #

I have:

• Read and followed KubeVela's contribution process.
• Related Docs updated properly. In a new feature or configuration option, an update to the documentation is necessary.
• Run make reviewable to ensure this PR is ready for review.
• Added backport release-x.y labels to auto-backport this PR if necessary.

How has this code been tested

Special notes for your reviewer

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: +0.10 🎉

Comparison is base (d19bb89) 60.58% compared to head (30d366a) 60.68%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5985      +/-   ##
==========================================
+ Coverage   60.58%   60.68%   +0.10%     
==========================================
  Files         224      224              
  Lines       31202    31202              
==========================================
+ Hits        18903    18935      +32     
+ Misses      10525    10492      -33     
- Partials     1774     1775       +1     

Flag	Coverage Δ
core-unittests	56.00% <ø> (+0.13%)	⬆️
e2e-multicluster-test	24.71% <ø> (ø)
e2etests	25.09% <ø> (-0.01%)	⬇️

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see 8 files with indirect coverage changes

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[Somefive]

LGTM