Cmdlets tests improvement.

[timayabi2020]

The task here entails:

• [x] Investigations on the available testing options for cmdlets. i.e. Pester, XUnit, NSubstitute and Raptor
• [ ] Document the test improvement plan and share it with internal team for review.
• [ ] Identify tasks arising from the reviewed document and create corresponding issues for tracking purposes.
• [ ] Implement the test plan as per the related issues above