Implement Custom User-Agent for Nutanix API Requests

[tuxtof]

/kind feature

Description

To improve observability and traceability when interacting with the Nutanix API, we should implement a custom User-Agent header in all outgoing API requests from this component.

Goals

• Clearly identify this component in Nutanix API logs and metrics.
• Facilitate debugging and support by making it easier to trace which tool is generating requests.
• Align with best practices for API consumption.

Proposed Format

The User-Agent should follow a structured format, such as:

<component-name>/<version>