Adds save/apply named settings profiles (SettingsProfileStore), a
battery-default export option that rewrites trainset velocity on
launch, and an option to omit decorative trainsets from the exported
scenery. Also surfaces many previously-unmapped eu07.ini keys in the
Settings UI (UART/feedback port, FPS limit, shadow angle, fullscreen
windowed, ANGLE Vulkan, friction/brake sensitivity, and an Advanced
section for texture/GLES/threading tunables).
