Enable operations to disable/enable sf cluster nodes as well as gracefully restart entire sf cluster

[arudell]

Description

This pull request introduces several new cmdlets to enhance the functionality of the SdnDiagnostics module and adds a utility function to test network accessibility. Below is a summary of the most important changes:

New cmdlets added to SdnDiagnostics.psd1:

• Added Confirm-SdnServiceFabricHealthy to validate the health of Service Fabric.
• Added Disable-SdnServiceFabricNode and Enable-SdnServiceFabricNode to manage Service Fabric nodes.
• Added Restart-SdnServiceFabricClusterNodes to restart cluster nodes in Service Fabric.

New utility function added to SdnDiag.Utilities.psm1:

• Introduced Test-ComputerIsAccessible to check if a computer is reachable over the network. It supports both immediate checks and waiting for accessibility with a configurable timeout and interval.

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.