Refactor module into small functions, with unit tests

[leojonathanoh]

Current

Module not subscribed to functional approach.

Expectation

Module subscribed to functional approach.

Discussion

In powershell, there is a strong convention of adopting a functional approach, where each cmdlet or function has its own file. Unit tests file are alongside the function.

Benefits:

• Unit testable
• Unit tests are documentation for the function
• Modular and reusable functions
• Non-monolithic approach makes it easier for contributors to open PRs for fixes or features.
• Improved debuggability