Azure: Have worker nodes backed by an encrypted disk

User Story:

As a user of HCP on Azure, I want to be able to provide a DiskEncryptionSet ID to encrypt the OS disks for the VMs in the NodePool so that the data on the OS disks will be protected by encryption.

Acceptance Criteria:

Description of criteria:

• Upstream documentation add on what is needed for the Azure Key Vault and how to encrypt the OS disks thru both the CLI and through the CR spec. 
• HyperShift CLI lets a user provide a DiskEncryptionSet ID to encrypt the OS disk.
• Ability to encrypt the OS disks through the HyperShift CLI.
• Ability to encrypt the OS disks through the HC CR.
• Any applicable unit tests.

Out of Scope:

N/A

Engineering Details:

• BYO resource group is required for this story.
• This story programmatically implements this Azure demo of using customer keys to encrypt the OS disk - https://learn.microsoft.com/en-us/azure/virtual-machines/disks-enable-host-based-encryption-portal?tabs=azure-powershell#deploy-a-vm-with-customer-managed-keys