Quality of Life changes to wgpu/js

[Daxode]

Makes wgpu.Color a [4]f32 to be more nice for odin (get all the fancy color.rggg stuff including wgpu.Color(1))

Also a tiny addition to js/events so you can do:

js.add_window_event_listener(.HashChange, nil, proc(e: js.Event) {
        buf := [256]u8{};
        val := js_ext.get_current_url(buf[:])
        fmt.println("Current URL:", val)
    })