Mock the actual behavior of fail_json

[baoy1]

Ansible faile_json will call sys.exit, then abort the execution, but currently we use FailJsonException to mock fail_json, that it cannot abort the execution.

Now mock fail_json to throw SystemExit to align with Ansible behavior.

All UTs are updated to extend PowerScaleUnitBase.

Description

A few sentences describing the overall goals of the pull request's commits.

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, pep8, linting, or security issues
• I have performed Ansible Sanity test using --docker default
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• Backward compatibility is not broken

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also list any relevant details for your test configuration

• UT

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.24%. Comparing base (b7de8d3) to head (bfe8972).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #173      +/-   ##
==========================================
- Coverage   90.54%   90.24%   -0.30%     
==========================================
  Files         145      143       -2     
  Lines       16695    16541     -154     
  Branches     2367     2365       -2     
==========================================
- Hits        15116    14928     -188     
- Misses        920      942      +22     
- Partials      659      671      +12     

Flag	Coverage Δ
units	90.24% <100.00%> (-0.30%)	⬇️

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[vangork]

As per the Codecov report, it brings missing and partial..

[baoy1]

As per the Codecov report, it brings missing and partial..

After adopting the same behavior as fail_json, some UTs coverage indeed went down, because the previous FailJsonException is caught and thrown to upper method caller.
Before issuing the PR, I've struggled for some days to fix UT errors (logic and design, etc), add test cases and improve the coverage. For now we have 90+% coverage, that meets the criteria already, so I am not planning to make the code coverage look appealing.

[vangork]

It is not the module code coverage, but the test case code coverage which is weired.

[P-Cao]

For codecov app, the stats are weird indeed. Maybe we can adopt a more reasonable way to calculate the coverage in future.

[baoy1]

Good catch. It is my fault. Used wrong indentation. Please recheck the result.