gracefully handle if servermanager not present

[arudell]

Description

This pull request updates the Get-EnvironmentRole function in src/modules/SdnDiag.Utilities.psm1 to handle scenarios where the Get-WindowsFeature cmdlet may not be available. The change ensures that the function gracefully handles environments lacking this cmdlet by returning a default value.

Key changes:

• Improved error handling for Get-WindowsFeature:
  • Added a check using Get-Command to verify the existence of the Get-WindowsFeature cmdlet before attempting to use it. If the cmdlet does not exist, the function now returns the default array @('Common') without attempting further operations.

Change type

• Bug fix (non-breaking change)
• Code style update (formatting, local variables)
• New Feature (non-breaking change that adds new functionality without impacting existing)
• Breaking change (fix or feature that may cause functionality impact)
• Other

Checklist:

• My code follows the style and contribution guidelines of this project.
• I have tested and validated my code changes.