Add all (43) C structures, from SDL2

[KohaAloha]

from here, -> https://wiki.libsdl.org/CategoryAPI

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SDL_AudioCVT
SDL_AudioSpec
SDL_Color
SDL_DisplayMode
SDL_DollarGestureEvent
SDL_DropEvent
SDL_Event
SDL_HapticCondition
SDL_HapticConstant
SDL_HapticCustom
SDL_HapticDirection
SDL_HapticEffect
SDL_HapticPeriodic
SDL_HapticRamp
SDL_JoyAxisEvent
SDL_JoyBallEvent
SDL_JoyButtonEvent
SDL_JoyHatEvent
SDL_KeyboardEvent
SDL_Keysym
SDL_MouseButtonEvent
SDL_MouseMotionEvent
SDL_MouseWheelEvent
SDL_MultiGestureEvent
SDL_Palette
SDL_PixelFormat
SDL_Point
SDL_QuitEvent
SDL_RWops
SDL_Rect
SDL_RendererInfo
SDL_Surface
SDL_SysWMEvent
SDL_SysWMinfo
SDL_SysWMmsg
SDL_TextEditingEvent
SDL_TextInputEvent
SDL_TouchFingerEvent
SDL_UserEvent
SDL_WindowEvent
SDL_assert_data
SDL_atomic_t
SDL_version