Traction Transformers Market Size, Share & Trends Analysis Report By Mounting Position (Underframe Mounted, Roof Mounted), By Voltage System (AC System, DC System, Multi-system), By Rolling Stock (Electric Locomotives, High-speed Trains, Metro Trains, Light Rail Vehicles, Electric Multiple Units, Diesel-Electric Locomotives), By Cooling Type (Oil-cooled, Air-cooled, Dry-Type) and By Country (U.S., Canada) Forecasts, 2026-2034