Add bulk snapshot script for VMs

[coelacant1]

Description

There is no script to bulk create snapshots of VMs. While VirtualMachines/Backup/BulkBackup.sh handles full backups, snapshots are a lighter-weight operation for creating point-in-time restore points. Operators need bulk snapshots before applying fleet-wide changes (e.g., OS updates, configuration changes).

A new script should be added under VirtualMachines/Backup/ or VirtualMachines/Operations/.

Acceptance Criteria

• New bulk snapshot script created
• Supports creating named snapshots across a VM ID range
• Supports optional snapshot description
• Supports vmstate option (include RAM state or not)
• Uses ArgumentParser.sh for argument handling