Corrugated and Folding Carton Packaging Market Size & Forecasts 2026-2035, By Segments (Product Type, Structure, End Use Industry), Growth Opportunities, Innovation Landscape, Regulatory Shifts, Strategic Regional Insights (U.S., Japan, China, South Korea, UK, Germany, France), and Competitive Dynamics (Smurfit Kappa, WestRock, International Paper, DS Smith, Mondi)