Add VM Template functuality

[darthVikes]

/kind feature

Describe the solution you'd like

Need the ability to change the VM into a Template or create a VM Template specifically so that you will then have it available to use to start to deploy new VMs from.

I believe this was a newer Nutanix Feature re: VM Templates

Anything else you would like to add:
Would like a force option? or ability to overright an existing template via name if you are recreating the same template.

Environment:

• packer-plugin-nutanix version (use packer plugins installed): 0.8.0
• Packer version (use packer version): 1.9.2
• OS (e.g. from /etc/os-release): Rocky 9.1

[tuxtof]

a valid use case we will put on roadmap, thanks