Global Network Security Appliances Market Size, Share Demand Report By Product Type (Firewall Appliances, Unified Threat Management, Intrusion Detection and Prevention Systems, VPN Appliances, Secure Web Gateway, Email Security, NAC, Advanced Threat Protection), By Deployment Type (On-Premise, Cloud-Based, Hybrid), By End-Use Industry (BFSI, IT & Telecom, Government & Defense, Healthcare, Retail & E-commerce, Energy & Utilities, Manufacturing, Education), By Region & Segment Forecasts, 2025–2030