Add bulk set firewall input/output policy script

[coelacant1]

Description

There is no dedicated script to bulk configure firewall input and output policies on VMs/LXCs. While Firewall/EnableFirewallSetup.sh sets a datacenter-level inbound policy, there is no script for per-VM/LXC policy configuration (ACCEPT, DROP, REJECT) for both inbound and outbound directions.

A new script should be added under Firewall/.

Acceptance Criteria

• New script Firewall/BulkSetFirewallPolicy.sh created
• Supports setting input policy (ACCEPT, DROP, REJECT) per VM/LXC
• Supports setting output policy (ACCEPT, DROP, REJECT) per VM/LXC
• Applies across a VM/LXC ID range
• Uses ArgumentParser.sh for argument handling