Add support to rotate a single server or loadbalancermux node certificate

[arudell]

This pull request adds support for performing certificate rotation on specific Load Balancer Mux and Server nodes within the SDN fabric by introducing a new optional ResourceRef parameter to the relevant cmdlets. The implementation ensures that if a ResourceRef is provided, operations are scoped to the specified node; otherwise, all nodes are targeted as before.

Enhancements to certificate rotation cmdlets:

• Added a new optional ResourceRef parameter to both Start-SdnMuxCertificateRotation and Start-SdnServerCertificateRotation functions, allowing users to specify a single resource (e.g., /loadBalancerMuxes/{name} or /servers/{name}) for targeted certificate rotation. [1] [2]
• Updated parameter definitions in both functions to support the new ResourceRef parameter across all parameter sets. [1] [2]

Conditional logic based on ResourceRef:

• Modified logic in both functions to query and operate only on the specified node if ResourceRef is provided, otherwise defaulting to all nodes. [1] [2]
• Ensured diagnostics installation is also scoped to the targeted node when ResourceRef is used, maintaining compatibility with previous behavior for all-nodes operations. [1] [2]

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.