Add v4 support for VMM

[abhimutant]

- CRUD for Virtual Machine
- CRUD for Images
- CRUD for Image Placement Policy
- Resource to Clone a VM
- Resource for NGT Installation / Uninstallation
- Resource for NGT upgrade
- Resource for Template deploy
- Resource for Template Guest OS Actions
- CRUD for Template
- Resource for CDROM inject/eject
- Resource for VM revert from recovery point
- Resource for VM guest customisation update
- Resource for VM Network Device Assign/Remove IP
- Resource for VM Network Device Migrate
- Resource for VM Shutdown Actions

[abhimutant]

Related PR: https://github.com/ideadevice/terraform-provider-nutanix/pull/34