video: Expose HDR metadata per-window

Moves the HDR properties from the display to be per-window, and adds the frog_color protocol to enable HDR under Wayland.

src/video/wayland/SDL_waylandvideo.h

@@ -83,6 +83,7 @@ struct SDL_VideoData
     struct xdg_wm_dialog_v1 *xdg_wm_dialog_v1;
     struct wp_alpha_modifier_v1 *wp_alpha_modifier_v1;
     struct kde_output_order_v1 *kde_output_order;
+    struct frog_color_management_factory_v1 *frog_color_management_factory_v1;
 
     struct xkb_context *xkb_context;
     struct SDL_WaylandInput *input;