Inflight Shopping Market Size, Share, and Industry Analysis By Airline Type (Full-Service Carriers (FSC), Low-Cost Carriers (LCC), and Charter Airlines), By Cabin Class (Economy, Premium Economy, Business, and First Class), By Product Category (Duty-Free (Cosmetics/Liquor), Travel Essentials, Electronics, and Local Souvenirs), By Point of Sale (Physical Cart, E-Commerce (Seatback/App), Pre-Order, and Crew-Assisted), and Regional Forecast, 2026-2034